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Direct Vent (Sealed Combustion) Forced Air Gas Furnaces
Installation InstructionsM2RC Series 90+ Upflow Condensing FurnaceM2RL Series 90+ Downflow Condensing Furnace
Upflow Model Downflow Model
! WARNING:Improper installation, adjustment,alteration, service, or maintenancecan cause injury or property damage.
Refer to this manual for assistance.For additional information consult aqualified installer, service agency, orthe gas supplier.
WARNING: Danger. Only qualified servicepersonnel shall be used to install and providemaintenance to this appliance.
Do not store or use gasoline orother flammable vapors and
liquids in the vicinity of this orany other appliance.
FOR YOUR SAFETY
• Do not try to light any appliance.
• Do not touch any electricalswitch; do not use any phone inyour building.
• Immediately call your gas supplierfrom a neighbor's phone. Followthe gas supplier's instructions.
• If you cannot reach your gassupplier, call the fire department.
• Extinguish any open flame.
DO NOT DESTROY. PLEASE READ CAREFULLY AND KEEP IN A SAFE PLACE FORFUTURE REFERENCE.
WHAT TO DOIF YOU SMELL GAS
2
Fuel TypeN - Natural Gas ReadyL - Propane (LP) Gas Ready
Cabinet WidthB - 19-3/4"
Airflow16 - 1600 CFM
Electrical CodeA - 1PH, 60 Hz, 120 VAC
Heating CapacityInput, BTUH (000’)
ApplicationM-Manufactured Home
Furnace Series
Comfort ModelRC - Condensing UpflowRL - Condensing Downflow
M 2 RC - 080 A - 16 - B N
Table 1. Model Identification
Lighting and Adjustmentof the Appliance ............................ 23
Electrical Wiring ..................................... 24Line Voltage Wiring .......................... 24Low Voltage Wiring .......................... 25
Ventilation ............................................... 26
Start-up and Adjustment ..................... 26Start-Up Procedure ......................... 26Shut Down Procedure ..................... 26Verifying and Adjusting Firing Rate . 26Verifying and Adjusting Temperature Rise .......................... 27Verifying Burner Operation .............. 28Verifying Operation of the Supply Air Limit Switch .................. 28
Description of Components ................ 28
Maintenance ........................................... 29Combustion Air and Vent System ... 29Air Filter(s) ....................................... 29Lubrication ........................................ 29Condensate Drain Assembly .......... 29Blower Compartment ....................... 29Heat Exchanger and Burner Maintenance .................................. 29
System Operation Information ........... 30Sequence of Operation .................... 30Furnace Fails to Operate ................ 31
Furnace Accessories ............................. 31
Location of Major Components .......... 32
Wiring Diagram ...................................... 33
Installation/PerformanceChecklist ......................................... 34
General ...................................................... 3Unit Dimensions ................................. 3Furnace Airflow Data ......................... 4Clearances to Combustible Materials 4Shipping Weights ................................ 4
Owner's Information ............................... 5
Installation Requirements ...................... 5Location .............................................. 6
Circulating Air Supply ............................ 6
Return Air Provisions .............................. 7
Air Distribution Systems ........................ 7
Upflow Furnace Installation .................. 8
Downflow Furnace Installation ............. 8
Venting and CombustionAir Requirements .......................... 11
Venting Requirements .......................... 11Vent Table ........................................ 12Vent Pipe Material ............................ 13Vent Pipe Length and Diameter ....... 13Vent Pipe Installation ........................ 14Pipe Routing & Support .................... 14Horizontal Venting ............................ 17Vertical Venting ................................ 17Vent Freezing Protection ................. 18
Drainage of Condensate From Furnace ................................ 18
Gas Supply and Piping ......................... 19Leak Check ...................................... 20High Altitude Derate ......................... 20
Conversion ............................................. 21
TABLE OF CONTENTS
3
Downflow Furnace
3/4" 3/4"
2 1/2"
LC LC
19 3/4"
10"
18 1/4"
CondensateDrainOutlet
7/8" Dia.Electric
Connection
1 1/2" x 2 1/2"KnockoutFor Gas
Connection
27 7/8"
19 3/4"
7/8" Dia. ElectricConnection
24 1/2"
3/4"
43"
21 7/8"
21 1/2"
15 1/2"21 1/2"
10 1/4"Bottom Supply AirOpening
(Side)
ExhaustVent
2"
1 1/2" x 3 1/2" Dia.Opening for
Gas Connection
3/4"
22 1/2"Exhaust Vent
Combustion Air Inlet
24 7/8" 24 7/8"
21 7/8"
21 1/4"
8"
20"
20 3/4"
19 3/4"
6 1/4"
20"
20 3/4"
A/C Coil Box
Bottom Supply Air Opening18 1/4"
Bottom Supply Air Opening
Return Air Opening
CondensateDrain Outlet
CombustionAir Inlet
19 3/4"
7 7/8"
Bottom Return Opening23"
19 3/4"
7/8" Dia. ElectricConnection
2 1/4"
43"
25 1/8"
25 1/4"
28"
25 1/4"
33"
CondensateDrain Outlet
CombustionAir Inlet
1 1/2" x 3 1/2" Dia.Opening for
Gas Connection
+
1 1/2" x 3 1/2" Dia.Opening forGas Connection
Bottom ReturnOpening
17"
ExhaustVent
25 5/8"
20 1/2"
20"
20 3/4"
+
7/8" Dia. ElectricConnection
23 1/4"
22 1/2"Exhaust Vent
30 1/4"
8"8"
1 1/4"1 1/4"
27 5/8"
20"
19 3/4"
Combustion AirInlet
19 1/2" 18 1/4"3/4" 1/2"
3/4"
6 1/4"
A/C Coil Box
3/4" 3/4"
3/4"
LC LC
CoverPlate
CondensateDrain Outlet
2 1/4"
1 3/8"
Upflow Furnace
Figure 1. Unit Dimensions
GENERAL
4
IMPORTANT: READ ALL INSTRUCTIONSCAREFULLY BEFORE BEGINNING THEINSTALLATION.
! WARNING:Do not use this product if any part hasbeen submerged under water.Immediately call a qualified servicetechnician to inspect the appliance andto replace any part of the control systemand any gas control that has beensubmerged under water.
Table 4. Minimum Clearances to Combustible Materials
* For Downflow model only. Upflow models can be 1".** 24 inches is the minimum clearance for servicing. 36 inches is the recommended clearance for service.
Table 3. Furnace Airflow Data
CAPACITIES —Furnace Airflow Data
* Factory wired cooling speed tap** Factory wired heating speed tap
- Not RecommendedNOTE: Data is for operation with filter.
NOTICE: Leave these instructions with the home-owner. Advise unit owner/user to follow the main-tenance recommendations outlined. Have a qual-
Table 2. Shipping Weights
! WARNING:Should overheating occur, or the gasfail to shut off, shut off the manual gasvalve to the appliance before shuttingoff the electrical supply.
ified service technician periodically check all wiringconnections and service unit as required.
The M2 series gas furnaces are listed drect vent(sealed combustion) forced air furnaces (typeFSP) for use with both natural and propane (LP)gases. The M2 furnace series has been certi-fied to the UL 307B standard for use in the UnitedStates and to ANSI Z21.47a-CAN/CGA-2.3a-1995 for use in the United States and Canada.
These furnaces may be installed in:
1. Manufactured Homes
2. Recreational Vehicles, Park Models
3. Manufactured Buildings
4. Modular Homes / Buildings
The M2 furnace is not to be used for the tempo-rary heating of buildings under construction.
CLEARANCES TO COMBUSTIBLE MATERIALSThis furnace is designed for the minimum clearances to combustible material listed in Table 4. Referto the furnace name plate, located inside the furnace cabinet, for specific model number and clearanceinformation.
M2RC - 080A - 16 - B(*) 160M2RC - 100A - 16 - B(*) 170M2RL - 060A - 16 - B(*) 170M2RL - 080A - 16 - B(*) 170M2RL - 100A - 16 - B(*) 175
A/C Coil Box 20*Can be N or L
Shipping Weight (lbs)Model
Furnace External Static Pressure (Inches Water Column)Furnace Input Motor Motor 0.1 0.2 0.3 0.4 0.5
Model No. Btuh Speed HP CFM Rise CFM Rise CFM Rise CFM Rise CFM RiseHigh * 1840 - 1780 - 1700 - 1630 - 1550 -
Med-High 1600 43 1560 44 1470 47 1400 49 1350 51Med-Low ** 1380 50 1350 51 1300 53 1250 55 1190 58
Low 1100 - 1050 - 1000 - 950 - 900 -High * 1910 - 1860 - 1780 - 1700 - 1620 -
Med-High ** 1640 53 1620 54 1540 57 1480 59 1420 62Med-Low 1440 61 1410 62 1370 64 1320 66 1270 70
Low 1230 - 1210 - 1180 - 1140 - 1090 -High * 1620 32 1560 33 1490 35 1430 36 1365 38
Med High 1450 36 1400 37 1350 38 1295 40 1240 42Med Low ** 1255 42 1225 43 1180 44 1145 45 1105 47
Low 1080 48 1055 49 1030 51 1000 52 960 54High * 1620 43 1560 45 1490 47 1430 49 1365 52
Med High 1450 49 1400 50 1350 52 1295 54 1240 57Med Low ** 1255 56 1225 57 1180 60 1145 61 1105 64
Low 1080 65 1055 67 1030 68 1000 70 960 73High * 1620 54 1555 57 1485 59 1425 62 1355 65
Med High ** 1430 62 1375 64 1330 66 1265 70 1210 73Med Low 1260 70 1220 72 1170 75 1130 - 1070 -
Low 1085 - 1050 - 1015 - 970 - 935 -
M2RL-060 60,000 1/2
M2RC-080
M2RC-100 100,000
80,000 1/2
1/2
1/2
1/2
80,000
100,000
M2RL-080
M2RL-100
Furnace Cabinet Minimum Clearances (Inches)Input Width Plenum Ductwork within(Btuh) (Inches) Side Vent Back Top* Front** Surfaces 3 ft. of Furnace60,000 19 3/4 0 0 0 10 0 1/4 1/480,000 19 3/4 0 0 0 10 0 1/4 1/4100,000 19 3/4 0 0 0 10 0 1/4 1/4
5
NOTICE TO INSTALLERInstaller is advised to follow carefully all in-structions and warnings in this manual to in-sure maximum performance, safety, and oper-ating efficiency of these appliances. Improperinstallation may create hazardous conditions,and will void the appliance warranty.
OWNER'S INFORMATION
About Your Central Furnace SystemNORDYNE has been involved in the design ofproducts for the manufactured home industrysince the first manufactured home or trailerwas built.
NORDYNE originated the sealed combustionsystem, which separates the furnace com-bustion system from the living area of the homeand is now a standard for the manufacturedhome industry.
NORDYNE engineers developed the first cen-tral heating system and the first central airconditioner for manufactured homes.
NORDYNE is dedicated to bringing to its cus-tomers the finest heating and cooling comfortpossible. NORDYNE constantly seeks to fur-ther refine its products to continuously provideexceptional comfort.
Follow the instructions in this booklet carefullyand this appliance will provide many years ofsuperior performance.
If you wish to cool your home automatically witha central air conditioning system investigatethe excellent NORDYNE cooling systems avail-able from your heating and cooling contractor.These systems are designed to work best withyour NORDYNE furnace and have been care-fully engineered to deliver optimal performancewhen mated with NORDYNE manufacturedhome furnaces.
NORDYNE also offers water heaters, fire-places and ventilating systems specificallydesigned for manufactured housing applica-tions. Ask your manufactured home retailer,your heating and cooling contractor, or yourdistributor for more information. Write directlyto the factory (PO Box 46911, St. Louis, MO63146) if you are unable to locate a source forNORDYNE manufactured housing products inyour area.
Manufacturer Warranty, Owner’sResponsibilities
It is the sole responsibility of the homeowner tomake certain the gas furnace has been cor-rectly installed in the home, converted to theproper fuel (LP gas or Natural gas), and ad-justed for proper operation.
A warranty certificate with full details is in-cluded with this furnace. However, NORDYNEwill not be responsible for any costs foundnecessary to correct problems due to im-proper setup, improper installation, furnaceadjustments, improper operating procedureon the part of the user, etc.
Some specific examples of service calls whichcannot be included in warranty payments are:
1. Converting the furnace to use anothertype of gas.
2. Repairing duct work in the home found tobe faulty.
3. Correcting wiring problems in the electri-cal circuit supplying the furnace.
4. Resetting circuit breakers, blown fusesor other switches.
5. Correcting problems due to improper gassupply pressure to the furnace.
6. Providing instructional training on how tolight and operate the furnace.
7. Correcting any problems caused by in-stallation of an air conditioner, heat pumpor other air comfort devices.
8. Revising installation of the furnace flueassembly.
9. Adjusting or calibrating of thermostat.10. Removing any construction debris which
has fallen into flue system.
Carefully review these responsibilities withyour manufactured housing dealer, servicecompany, or gas supplier, so that there will beno misunderstanding at a later time.
INSTALLATION REQUIREMENTSRequirements and Codes:The installer must be familiar with and complywith all local codes and regulations applicableto the installation of heating appliances andrelated equipment. In the absence of localcodes, the installation must conform with theseinstructions and the current provisions of oneor more of the following standards:
a. Federal Manufactured HomeConstructions & Safety Standard (H.U.D.Title 24, Part 3280.707[a][2])
6
able and allow the appropriate clearance foryour installation.
This furnace is certified for use on woodflooring. The furnace must be installed on asolid surface and must be level front to backand side to side. This furnace must not beinstalled directly on carpeting, tile, or anycombustible material other than wood flooring.Downflow models can only be installed oncombustible flooring when installed on aNordyne plenum base (part numbers 901987through 901993 - see Table 5). Both the upflowand downflow models must be installed withthe Nordyne A/C coil box (part no. 914958).
The plenum attached to the A/C coil box andthe ductwork within 3 feet of the furnace mustbe installed such that surfaces are at least1/4" from combustible construction.
CIRCULATING AIR SUPPLY
GeneralPlenums and air ducts must be installed inaccordance with the Standard for theInstallation of Air Conditioning and VentilatingSystems (NFPA No. 90A) or the Standard forthe Installation of Warm Air Heating and AirConditioning Systems (NFPA No. 90B).
! WARNING:Products of combustion must not beallowed to enter the return air openingsof the furnace or the circulating air supply.Failure to prevent products ofcombustion from being circulated intothe living space can create potentiallyhazardous conditions including carbonmonoxide poisoning that could result inpersonal injury or death.
The floor or platform on which the furnaceis mounted must provide sound physicalsupport of the furnace with no gaps,cracks, or sagging between the furnaceand the floor or platform.
The circulating air ductwork must not beconnected to any other heat producingdevice such as a fireplace insert, stove,etc.
b. The Standard for Manufactured HomeInstallations (Manufactured Home Sites,Communities, and Set-Ups) ANSI A225.1and/or CAN/CSA-2240 MH Series).
c. American National Standard (ANSI-119.2/NFPA-501C) for all recreationalvehicle installations.
d. American National Standard (ANSI-Z223.1/NFPA-54) and/or CAN/CGAB149 for all gas-fired furnace models.
e. American National Standard (ANSI-C1/NFPA-70) and/or CSA 22.1 CanadianElectric Code Part 1 for all electrical fieldwiring.
CE générateur d'air chaud doit être installéconformément aux instructions du fabricant etaux codes locaux. En l'absence de code local,respecter la norme ANSI Z223.,1, institulé Na-tional Fuel Gas Code ou les codes d'installationCAN/GCA-B149.
The National Fuel Gas Code is available bywriting:
American National Standards Institute,Inc.1430 BroadwayNew York, NY 10018
NFPA publications are available by writing:
National Fire Protection AssociationBatterymarch ParkQuincy, ME 02269
LocationThe furnace must be installed on a level sur-face, and as close to the center of the airdistribution system as possible. See Figure 1for overall dimensions to determine the re-quired clearances in hallways, doorways, stairs,etc. to allow the furnace to be moved to theinstallation point. The furnace must be installedso that all electrical components are protectedfrom water.
Minimum clearances to combustible materialsare listed in Table 4. Access for positioning andservicing must be considered when locatingthe unit. 24 inches is the minimum requiredclearance for servicing the unit. 30 inches is theminimum required clearance for positioning theunit. 36 inches is the recommended clear-ance from the front of the unit. Please notethat a panel or door can be located such thatthe minimum clearance on the rating plate issatisfied, but that panel or door must be remov-
7
RETURN AIR PROVISIONS
Upflow models draw the return air from thebase of the furnace. A stand or return air ductmust be supplied to the furnace to provide therequired return air.
Downflow models draw the return air from thetop of the furnace. The minimum requiredclearance to the top of the furnace is detailedon the furnace rating plate. Additional clear-ance may be required depending upon filteraccessibility.
For each application, the U.S.A. home manufac-turer shall comply with all of the following condi-tions to have acceptable return air systems forcloset installed forced air heating appliances:
a. Regardless of the location, the return airopening into the closet shall not be lessthan specified in the appliance’s listing.
b. Means shall be provided to preventinadvertent closure by a flat object placedover the return air opening when it islocated in the floor of the closet (versusthe vertical front or side wall).
c. The cross-sectional area of the returnduct system leading into the closet shallnot be less than 390 square inches.
d. The total free area of openings in the flooror ceiling registers serving the return airduct system must be at least 352 sq. in.At least one register should be locatedwhere it is not likely to be covered bycarpeting, boxes and other objects.
e. Materials located in the return ductsystem must have a flame spreadclassification of 200 or less. This includesa closet door if the furnace is in a closet.
f. Noncombustible pans having 1" upturnedflanges are located beneath openings ina floor duct system.
g. Wiring materials located in the returnduct system shall conform to Articles300-22 of the National Electrical Code(ANSI C1/NFPA-70).
h. Gas piping is not run in or through thereturn duct system.
i. Test the negative pressure in the closetwith the air-circulating fan operating athigh speed and the closet closed. Thenegative pressure is to be no morenegative than minus 0.05 inch watercolumn.
j. For floor return systems, themanufactured home manufacturer shallaffix a prominent marking on or near theappliance where it can be easily readwhen the closet door is open. Themarking shall read:
! CAUTION:HAZARD OF ASPHYXIATION: Do notcover or restrict return air opening.
k. Air conditioning systems may requiremore duct, register and open louver areato obtain necessary airflow. UseNORDYNE’s certiduct program todetermine proper duct size for A/C.
AIR DISTRIBUTION SYSTEMS
For proper air distribution, the supply ductsystem must be designed so that the staticpressure measured external to the furnacedoes not exceed the listed static pressurerating shown on the furnace rating plate.
Three typical distribution systems are illustratedin Figure 2. Location, size, and number ofregisters should be selected on the basis ofbest air distribution and floor plan of the home.
Figure 2. Typical Supply Duct System
A Single trunk duct
B Dual trunk ductw/crossover connector
CTransition duct w/branches
x
SUPPLY AIR DUCT
FLOOR CAVITY(depth equal to "X" in Figure 5 and Table 5)
Figure 3. Floor Cavity Cut-Out
8
13 1/4"
10 1/4"
19” 19
"
Figure 4. Top View of Duct Connector
If "X" (Floor cavity) is:
7/8" (22mm) 901987
2" (51mm) 901988
4 1/4" (108mm) 901989
6 1/4" (159mm) 901990
8 1/4" (210mm) 901991
10 1/4" (260mm) 901992
12 1/4" (311mm) 901993
Use Duct Connector Model
Table 5. Duct Connectors
X
SEE TABLE 5
REDUCER
FELT-SEAL
SPACERS
C
OPENING TO DUCT
WITH PLATE (C) REMOVEDOPENING BECOMES13-1/4” x 13-1/4”
Figure 5. Duct Connector
UPFLOW FURNACEINSTALLATION
a. Position the furnace on top of the returnair ductwork or return air stand. NOTE:The ductwork or stand must have anopening equal to that of the return airopening of the furnace. Refer to Figure 1for the proper return air opening size.Secure the furnace to the floor or baseonce it has been properly positioned.
b. Position and secure the A/C coil box tothe top of the furnace. The A/C coil box
can be secured to the furnace using theprovided attachment brackets. Thesebrackets are designed to attach thefurnace cabinet to the A/C coil box on thesides. To install these brackets, positionone bracket on the side of the furnace,so that the locating dimples are in thegroove created by the top of the furnacecabinet and the bottom of the A/C coilbox. Using the provided self-drillingscrews, secure the bracket to the A/Ccoil box and the furnace. Repeat on theother side of the furnace for the otherbracket.
c. Attach the plenum from the supply ductto the flanges of the A/C coil box.
d. Secure the plenum to the supplyductwork.NOTE: Additional fasteners may be usedat rear, sides or through door frame, asdesired, to secure furnace to closet oralcove framing.
DOWNFLOW FURNACEINSTALLATION
DUCT CONNECTOR SELECTION FORDOWNFLOW MODELS
a. Determine depth of floor cavity fromsurface of floor to top of supply air duct(See Figure 3).
b. Select appropriate model from Table 5which matches X-dimension of the floorcavity. To maximize air delivery, removereducer “C” (see Figure 5) to obtain thelargest open area that will fit the duct/floor construction.
INSTALLATION OF THE DUCT CONNEC-TOR FOR DOWNFLOW INSTALLATIONSRequired cut-out openings in the floor, ceiling,roof, and/or walls must be carefully located toavoid misalignment of the furnace, combustionair piping, and vent piping (see Figures 14-16).Installation procedures are suggested fortypical furnace installations and need not befollowed in the exact listed sequence.
CUT OUT FLOOR OPENING FORDOWNFLOW MODELS
a. Determine center of closet or alcove(Figure 7).
b. Locate center of the floor opening, mea-sured 10" from the rear wall, and markcut-out measuring approximately 14-1/2" by 14-1/2" (± 1”) for model ductconnector used (refer to Figures 6 & 7).
9
Figure 6. Cut-Out Locations
25 1
/8"
(Up
flo
w M
od
els)
21 7
/8"
(Do
wn
flo
w M
od
els)FLOOR CUT-OUT
FOR DUCT CONN.
CL
CL
14-1
/2"
2-1/
4"
2-3/4"
20"
14-1/2"
13-1
/2"
CA
SE
D C
OIL
WR
AP
PE
R O
UTL
INE
REAR WALL OF CLOSET OR ALCOVE
FuelLineHole
Alt. FuelLine Hole
25 1
/8"
(Up
flo
w M
od
els)
21 7
/8"
(Do
wn
flo
w M
od
els)
Figure 7. Closet or Alcove Floor Cut-Out
10"
FLOOR OPENING
CLCL
SIDE WALLREAR WALL
FUEL LINE HOLE
25 1/8" (Upflo
w Models)
21 7/8" (Downflo
w Models)
Figure 8. Mounting Plate
REAR WALLMOUNTING PLATE
FLOOR OPENING
FUEL LINE HOLE
SUPPLY AIR DUCT
CUT DUCT OPENING1/16TH. LARGER THAN DUCT CONNECTOR
ALT.FUEL LINE HOLE
Figure 9. Duct Connector
REAR WALL
SUPPLY AIR DUCT
ALT.FUEL LINE HOLE
MOUNTING PLATE
FLOOR OPENING
BEND CONNECTOR TABSUNDER DUCT OPENING
FUEL LINE HOLE
CUT DUCT OPENINGa. Place duct connector through the floor
opening with bottom tabs resting ontop of the supply air duct.
b. Center duct connector and push backagainst rear edge of floor opening.
c. Mark cut-out location (tab area) andremove duct connector.
d. Cut out duct opening 1/4" larger thanarea marked.
10Figure 12. Alternate Installation
Staple Folded DuctFlap (typ) to side of Duct
Connector
Duct
STEP 4.
STEP 1.
"A" "A"
"B"
"B" Cut- Out Area"A"
Cut- Out Area "A"
Fold Back Flap "B"
Fold Back Flap "B"
Top of Duct
"A" "A"
STEP 2.
"B"
"B"
Fold Back Flap"B"
CutLines Duct
Fold Back Flap"B"
STEP 3.
Bend Duct Connector Tabs Upand Over- (along length of duct)
DuctFlap "B"
Duct
Duct
Duct Connector
Narrow Duct
Figure 11. Narrow Duct Installation
INSTALL FURNACE MOUNTING PLATEa. Bend tabs on furnace mounting plate
upwards 90°b. Place mounting plate (supplied within
duct connector) at rear of the flooropening (See Figure 8).
INSTALL DUCT CONNECTORa. Place duct connector through the floor
opening with bottom tabs extendingthrough the duct opening. (See Figure 9)
b. Secure duct connector to floor.c. Bend bottom tabs under and up tightly
against the supply air duct (See Figure10).
NOTE: The duct connector is designed foruse on ducts 12" in width. When using theconnector on 12" wide ducts, there may beinsufficient clearance to bend the tabs on twosides of the duct connector. In such cases thetabs may be attached to the sides of the ductby using sheet metal screws or other suitablefasteners. (See Figure 11).
If tape is used to provide a better seal, it shouldbe approved by applicable national or local codes.
ALTERNATE ATTACHMENT METHODSThis procedure may also be used to install afurnace duct connector to narrow metalductwork where insufficient clearance preventsbending of the duct connector tabs at theside(s) of the duct. (See Figure 12).1. Score and cut the top of the metal duct as
indicated in Step 1 or Step 2. With Step 1choice, also cut out the metal from theshaded area “A”.
2. Fold the duct flap “B” up, (See Step 3).3. At the front-to-back of duct run (Area
“A”), bend the duct tabs and secure themdirectly to the duct.
Figure 10. Installation of Duct Connector
TABS TABS
DUCT DUCT
1. INSERT DUCT PLENUM CONNECTOR INTO DUCT CUT-OUT.
2. BEND BOTTOM TABS OVER AND ONTO THE UNDERNEATH DUCT SERVICE.
11
4. At area “B”, bend the duct tabs up andback over, around the duct connector,(See Step 3).
5. Fold/form the duct flap against the side ofthe duct connector and attach as shown,(See Step 4). Use three (3) staples(minimum) on each duct flap OR, if a 2Xblock/joist is not provided, use two (2)sheet metal screws (minimum) on eachduct flap. An alternate attachment methodis acceptable, as long as the plenum issecurely attached.
6. Tape the duct flap edges with an approvedtape for a leak-free joint.
INSTALL DOWNFLOW FURNACEa. Prepare the A/C coil box as described in
the instructions provided with the coil box.b. Place A/C coil box onto duct connector.c. Slide A/C coil box back until it is firmly
against the mounting plate. Mountingplate tabs should be bent upwards so asnot to interfere with furnace.
d. Secure front with one (1) fastener ateach corner through front bottom flangeand through the back of the A/C coil box.
e. Position the furnace on top of the A/C coilbox. Ensure that the furnace is properlypositioned on the wrapper.
f. Secure the A/C coil box to the bottom ofthe furnace. The A/C coil box can besecured to the furnace using the providedattachment brackets. These bracketsare designed to attach the furnacecabinet to the A/C coil box on the sides.To install these brackets, position onebracket on the side of the furnace, so thatthe locating dimples are in the groovecreated by the bottom of the furnacecabinet and the top of the A/C coil box.Using the provided self-drilling screws,secure the bracket to the A/C coil boxand to the furnace. Repeat on the otherside of the furnace for the other bracket.
NOTE: Additional fasteners may be used atrear, sides or through door frame, as desired,to secure furnace to closet or alcove framing.
VENTING AND COMBUSTION AIRREQUIREMENTS
! CAUTION:Snow must not be allowed to restrict orblock the combustion air intake or ventpipes.
GeneralNORDYNE condensing furnaces must beinstalled with outdoor combustion air pipeddirectly to the furnace. Codes refer to this typeof installation as direct vent, or two pipeinstallation.
Provisions must be made for adequate supplyof air for combustion and ventilation. For UnitedStates installations, the adequacy of airprovisions can be determined by consultingthe current version of the National Fuel GasCode (ANSI Z223.1/NPFA-54). For Canadianinstallations, requirements are specified in theNational Standard of Canada (CAN/CGAB149.1 & .2). Consult local codes for specialrequirements.
NOTE: If the furnace is operated withoutadequate air for combustion and ventilation, itmay not perform properly. Furnacecomponents may be strained by hightemperature and could fail prematurely.
! WARNING:The combustion air piping must not beblocked or restricted in any manner.
! WARNING:Furnace installation using methods otherthan those described in the followingsections must comply with the NationalFuel Gas Code and all applicable localcodes to provide sufficient combustionair for the furnace.
VENTING REQUIREMENTS
! WARNING:FURNACE MUST NOT BE COMMONVENTED WITH OTHER APPLIANCES.
GeneralThis section specifies installation requirementsfor 2-pipe combustion air piping. The capacitytable provided in this section applies to the totalsum of vent and combustion air piping lengths.
12
*NOTES1. Subtract 3.5 ft. for each additional 3" elbow.2. Two 45 degree elbows are equivalent to one 90 degree elbow.3. One short radius elbow is equivalent to two long radius elbows.4. Do not include termination elbows in calculation of vent length.5. This table is applicable for elevations from sea level to 2000 ft. For higher elevations,
decrease vent pipe lengths by 8% per 1000 ft. of altitude.6. Only the above pipe materials are approved for use with these condensing furnaces.
These condensing furnaces are classified as"Category IV" appliances, which require specialventing materials and installation procedures.Category IV appliances operate with positivevent pressure and therefore require ventsystems which are thoroughly sealed. Theyalso produce combustion condensate, whichis slightly acidic and can cause severecorrosion of ordinary venting materials.Furnace operation can be adversely affectedby restrictive vent and combustion air piping.Therefore, vent and combustion air pipinglengths must conform completely to therequirements of Table 6.
The furnace must be vented to the outdoors.It must not be vented in common with any otherappliance, even if that appliance is of thecondensing type. Common venting can resultin severe corrosion of other appliances or theirventing and can allow combustion gases toescape through such appliances or vents. Donot vent the furnace to a fireplace chimney orbuilding chase.
If removing an existing furnace in a ventingsystem, the venting system may not be properlysized. To test the vent system with theremaining appliances, follow the test outlinedbelow.
The following steps shall be followed with eachappliance connected to the venting system placein operation, while any other appliances con-nected to the venting system are not in operation:
a. Seal any unused openings in the ventingsystem.
b. Inspect the venting system for propersize and horizontal pitch, as required inthe National Fuel Gas Code, ANSI Z223.1or the CAN/CGA B149 Installation Codesand these instructions. Determine thatthere is no blockage or restriction,leakage, corrosion and other deficiencieswhich could cause an unsafe condition.
c. In so far as is practical, close all buildingdoors and windows and all doors betweenthe space in which the appliance(s)connected to the venting system arelocated and other spaces of the building.Turn on clothes dryers and any otherappliance not connected to the ventingsystem. Turn on any exhaust fans, suchas range hoods and bathroom exhausts,so they shall operate at maximum speed.Do not operate a summer exhaust fan.Close fireplace dampers.
d. Follow the lighting instructions. Placethe appliance being inspected inoperation. Adjust thermostat so applianceshall operate continuously.
e. Test for draft hood equipped appliancespillage at the draft hood relief openingafter 5 minutes of main burner operation.Use the flame of a match or candle.
f. After it has been determined that eachappliance connected to the ventingsystem properly vents when tested asoutlined above, return doors, windows,exhaust fans, fireplace dampers andany other gas burning appliance to theirprevious conditions of use.
Table 6. Vent Table
DIRECT VENT, DUAL PIPE LENGTH (ft.)with 1 long radius elbow on each pipe.*
PVC,CPVC or ABS Inlet/Outlet
SCH. 40 Pipe Size 3" 3"
50 50
90 90
90 90
Model M2RC/L 080
Model M2RC/L 100
Model M2RL 060
APPLICATION
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Vent Pipe MaterialVent and combustion air pipe and fittings mustbe one of the following materials and mustconform to the indicated ANSI/ASTM standards:
Material StandardSchedule 40 PVC D1785
PVC-DWV D2665SDR-21 D2241
& SDR-26ABS-DWV D2661
Schedule 40 ABS F628Foam/Cellular Core PVC F891
Cement and primer must conform to ATSMStandard D2564 for PVC and Standard D2235for ABS. When joining PVC piping to ABS, usean appropriate solvent cement and procedureper the piping manufacturer's recommendationand ASTM Standard D3138.
Vent Pipe Length and DiameterIn order for the furnace to operate properly, thecombustion air and vent piping must not beexcessively restrictive. To ensure this useTable 6, which indicates the maximum allowablepiping length for a furnace of specified inputrate, when installed with piping of selecteddiameter and number of elbows. This tableapplies to the length and number of elbowsfor each pipe. To use the table, the furnaceinput rate, the centerline length and the numberof elbows on each pipe must be known. Choosethe diameter for which the tabulated length isequal to or greater than required.
Use of the table is illustrated in the followingexamples:
Example:An 80,000 Btuh furnace is to be installedin a "two-pipe" system with 40 feet of ventpiping. There are four elbows, excludingthose exterior to the building.
Solution:Consulting Table 6, in the dual pipe lengthcolumn for an 80,000 Btuh furnace, themaximum allowable length for a 3" inlet/3" outlet is 90 feet with one elbow. Select3" pipe. For two additional elbows, deduct3.5 ft. for each elbow, or 7.0 ft. for amaximum installed vent length of 83 ft.
Condensing furnace combustion productshave very little buoyancy, so Table 6 is to beused without consideration of any vertical risein the piping.
g. If improper venting is observed duringany of the above tests, the ventingsystem must be corrected.
Procéder comme suit pour chaque appareilraccordé à la tuyauterie d'évacuation et en étatnormal de fonctionnement; tous les autresappareils raccordés à la même tuyauteried'évacuation doivent être mis hors service:
a. sceller toute ouverture non utilisée de latuyauterie d'évacuation
b. s'assurer que la tuyauterie d'évacuationprésente des dimensions et une pentehorizontale conformes à la norme ANSIZ223.1, intitulée National Fuel Gas Codeou aux codes d'installation CAN/CGAB149, ainsi qu'aux présentesinstructions. S'assurer que la tuyauterien'est pas bloquée, restreinte, corrodée,qu'elle ne fuit pas et qu'elle ne présenteaucun autre défaut potentiellementdangereux.
c. dans la mesure du possible, fermer toutesles portes et fenêtres du bâtiment, ettoutes les portes entre la pièce où setrouve l'appareil raccordé à la tuyauteried'évacuation et les autres pièces dubâtiment. Mettre en service lesséccheuses et tout autre appareil quin'est pas raccordé à la tuyauteried'évacuation. Faire fonctionner à régimemaximal tout ventilateur d'évacuation,tel que les hottes de cuisinière et lesventilateurs de salles de bains. Ne pasmettre en service les ventilateurs d'été.Fermer les registres des foyers.
d. respecter les instructions d'allumage.Mettre en service l'appareil à l'essai.Régler le thermostat de manière à ce quel'appareil fonctionne sans interruption
e. S'assurer qu'un appareil muni d'uncoupe-tirage ne présente aucune fuite àl'ouverture du coupe-tirage après que lebrûleur principal ait fonctionné pendantcinq minutes. Employer la flamme d'uneallumette ou d'une chandelle.
f. Après avoir déterminé que tous lesappareils raccordés à la tuyauteried'évacuation évacuent correctment telque prescrit ci-dessus, rouvrir les porteset les fenêtres et remettre les ventilateursd'évacuation, les registres de foyers ettout autre appareil fonctionnant au gazàleur état de fonctionnement initial.
g. Si un appareil n'évacue pas correctementà la suite de l'un des essais ci-dessus,corriger la tuyauterie d'évacuation.
14Figure 13. Vent Termination Clearances
4 ft. min
12 in. min
12 in. min
12 in. m
in
9 in.
4 ft. min
12 in. min
12 in. min
Mechanicaldraft vent terminal
Direct ventterminal50,000 Btuhor less
Forced Air Inlet
Direct ventterminal - more than50,000 Btuh
Mechanical draft vent terminal
Mechanical draft vent terminal
Grade
Less than 10 ft.
3 ft. min.
NOTE: Always use the same or larger sizepiping for combustion air as is used for theexhaust vent.
Vent Pipe InstallationPipe Routing and SupportRoute piping as directly as possible betweenthe furnace and the outdoors and rememberthat routing affects pipe size requirements perthe preceding section. Locate the combustionair intake and the vent exhaust in the sameatmospheric pressure zone - i.e. both must exitthe building though the same portion of exteriorwall or roof. Vent piping must be sloped upwardsnot less than 1/4" per foot in the direction fromthe furnace to the terminal. This is to ensurethat any condensate flows back to the furnace(where it can be disposed of through thecondensate disposal system).
! CAUTION:Combustion air must not be drawn froma corrosive atmosphere.
The quality of outdoor air must also beconsidered. Be sure that the combustion airintake is not located near a source of solventfumes or other chemicals which can causecorrosion of the furnace combustion system.
Piping must be mechanically supported so thatits weight does not bear on the furnace. Supportsmust be at intervals no greater than five feet,and at smaller intervals if necessary to ensure
that there are no sagging sections to trap water(See Figures 14 & 15).
Figure 16 illustrates vent and combustion airpipe sizes exiting the furnace. Transition to thecorrect pipe size must be done close to thefurnace so that the full length of pipe is of propersize.
These condensing furnaces have been certifiedfor installation with zero clearance betweenvent piping and combustible surfaces. However,it is good practice to allow space for conveniencein installation and service.
Pipe Couplings at the FurnaceThe provided rubber couplings should be in-stalled in the combustion air (use 3” diametercoupling) and vent (2” diameter) pipes to allowfor servicing. These couplings are designed tofit snugly over the pipe and be secured to thepipes using the provided hose clamps. Use 3"x 2" flexible coupling at furnace on 2" vent pipeand on upflow units use 3" diameter couplingabove coil box, as shown in Figures 14 and 15.Refer to figures 14 and 15 for the properinstallation of these couplings.
Location of Outdoor TerminationsVent and combustion air intake terminationsmust be located to ensure proper furnaceoperation and to conform to applicable codes.Figure 13 illustrates necessary distances fromthe vent termination to windows andbuildingair intakes. In Canada, the Canadian FuelGas Code takes precedence over these
15
5/8"
Inlet Exhaust
Top ViewCombustion
Air Inlet
Offset with ExhaustPipe for Adequate
Dimensional Clearance
PVC or ABSPipe
Exhaust Vent
First Support, located asclose to furnace as possible
3" diameter Neoprene Coupling*
w/ 2 Clamps
3" Coupling
A/C CoilBox
Furnace
See Vent Table
Straps or other suitable supports at minimum 5 foot intervals
Upward Pitch - 1/4" per FootOutlet Exhaust Vent
Seal/Cualkaround pipeat building
90˚ Elbow
12"Min.
7"Wall
Normal Snow Level
Flexible 3" x 2" reducer to adapt the 2" diameter vent pipe of furnace to the 3" diameter pipe of the vent
Upflow Furnace
Seal/CaulkAround Pipeat Building
90˚ Elbow
12"Min.
Normal Snow Level
Wall
First Support Should be as Close toFurnace Connection as Possible
Exhaust VentFurnace
3" diameterNeoprene Coupling*and 2 Clamps
PVC orABS pipe
Offset with ExhaustPipe for AdequateDimensional Clearance
Combustion Air Inlet
5/8"InletExhaustSee Vent Table 4
Straps or Other SuitableSupports at Minimum of
5 ft. Intervals
Upward Pitch - 1/4" Per FootOutlet Exhaust Vent
Top View
Flexible 3" x 2" reducer to adapt the 2" diameter vent pipe of furnace to the 3" diameter pipe of the vent
Downflow Furnace
instructions. Specifically, all minimumdistance requirements with respect totermination of the vent piping listed below.
The following list is a summary of vent terminallocation requirements:1. The termination must be 12 inches above
snow level or grade level whichever ishigher. See Figure 17 for alternate methodto achieve 12" above snow level.
2. The minimum distance for a direct vent (2-pipe) installation) from any door,(openable) window, or air gravity inlet is 1ft. below, 1 ft. horizontally, or 1 ft. above.
3. The vent termination shall be a minimum of3 ft. above any forced air inlet within 10 ft.
4. The vent termination shall be located atleast 4 ft. horizontally from any electric
meter, gas meter, regulator and any reliefequipment. These distances apply ONLYto U.S. installations. In Canada, the Ca-nadian Fuel Gas Code takes precedence.
5. Avoid areas where condensate drainagemay cause problems by dropping onplanters or patios, etc. Also ensure thatexhaust gases will not impinge on win-dows or building surfaces, which may becompromised or damaged by condensa-tion. Do not install the vent terminal suchthat exhaust is directed into window wells,stairwells, under decks or into alcoves orsimilar recessed areas, and do not termi-nate above any public walkways.
6. Select the point of wall penetration wherethe minimum 1/4 inch per foot of slope upcan be maintained.
Figure 14. Horizontal Venting* These neoprene couplings are field-supplied and can be used if the installation requires
breakable connections in the piping. Note that a maximum of two couplings per pipe are allowed.
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RubberCouplingw/ 2 Clamps
3" Coupling A/C CoilBox
Furnace Front
Furnace
3" diameterNeoprene Coupling*w/ 2 Clamps
Support Systemon Vertical Rise
Below Joints
Exhaust Vent
Support System with first supportas close to the furnace as possible
Upward Pitch1/4" per foot
CombustionAir Pipe
5'
Flexible 3" x 2" reducer to adapt the 2" diameter vent pipe of furnace to the 3" diameter pipe of the vent
Furnace
3" diameterNeoprene Coupling*w/ 2 Clamps
ExhaustVent Combustion
Air Pipe
Support Systemon Vertical Rise
Below Joints
Support System with first supportas close to the furnace as possible
5'
Upward Pitch1/4" per Foot
Flexible 3" x 2" reducer to adapt the 2" diameter vent pipe of furnace to the 3" diameter pipe of the vent
Upflow Furnace
Downflow Furnace
Combustion Air Inlet3" PVC on 080/100 models
2" PVCExhaust VentAll Models
Furnace Top
Figure 15. Vertical Venting
Downflow Furnace
Use appropriate adaptor for connection to furnace.
Upflow Furnace
Figure 16. Furnace Pipe Adaptions
Use appropriate adaptor for connection to furnace.
Combustion Air Inlet Pipe Collar Diameter 3" for coupling or reducer
Furnace Top
2" PVC Exhaust Vent All Models
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! CAUTION:For optimal performance vent furnacethrough wall which experiences the leastexposure to winter winds.
Horizontal VentingVent and combustion air intake terminationsmust be as shown in Figure 18.
! WARNING:Ensure that the combustion air vent andthe exhaust vent are configured asshown in Fig. 18. Improper venttermination can cause recirculation ofthe flue gases. This may result in furnacevibration. In severe cases, the furnacewill cycle, due to the intermittent contactbetween the flame and the flame sensor.If you note these oscillations occurring,check the vent configuration. Make surethat the exhaust vent does not have a 90degree termination.
For Canadian installations please refer to theCanadian Installation Code (CAN/CGA-B149.1or 2) and/or local codes.
For horizontal venting, one of the following kitsis recommended:
The kit consists of two face plates and aninsulating gasket to seal the exterior surface.A hole sized closely to the pipe diameter mustfirst be cut through the wall. A short length of
Table 7. Vent Protection
‡ = Insulation thickness greater than 3/8 inch, based on an R valueof 3.5 (ft*°F*hr)/(BTU*in)
pipe is then cut such that it can penetrate thewall and be held in place by closely fittingstandard couplings. The face plates are re-tained on both sides of the wall by the couplings,and the gasket is retained against the wall bythe outer face plate. Face plates must befastened to the wall and the outside one mustbe flashed as appropriate to prevent entry ofwater.
When the above kits are not used the followingsteps are required:1. Check the hole size cut through the exte-
rior wall. Insure that the hole diameter isless than the diameter of the couplings tobe used.
2. Extend the vent pipe through the wallapproximately 1" and seal the area be-tween the wall and pipe.
3. Apply couplings to the vent pipe on theinterior and exterior sides of the wall toinsure the pipe can not be pushed orpulled through the wall.
4. Insure the combustion air inlet pipe has a 90degree termination elbow, and is pointingdownward as shown in Figures 18 & 19.
Note that a combustion air intake must beprovided with an elbow opening downward.
When the vent pipe must exit an exterior wallclose to the grade or expected snow level, ariser should be provided as shown in Figure 17.Insulation is required to prevent freezing of thissection of pipe.
Table 7 describes the maximum length of fluepipe that can travel through an unconditionedspace or an exterior space. The total ventlength must not exceed the lengths noted onTable 6.
Vertical VentingFigure 19 shows the proper installation andclearances for vertical vent termination. The
Winter Design Termperature (°F)
Without Insulation (feet)
With Insulation (feet) ‡
Maximum Flue Pipe Length in Unconditioned and Exterior Spaces
70
70
60
0
20
-20
45
20
10
3" PVC Horizontal Exterior Vent Mounting Kit
9023750
18
Figure 18. Exhaust and CombustionAir Pipe Clearances
36" max.12" min.
Exhaust VentOption B
Exhaust VentOption A
Exhaust VentOption C
Mounting KitFaceplate Secured
to Wall with Screws 12" Min.36" Max.
12" Min.36" Max.
7" Min.
8" Min.
12" Min. toNormal Snow Level
CombustionAir Inlet
Grade Levelor NormalSnow
Inlet Exhaust
roof penetration must be properly flashed andwaterproofed with a plumbing roof boot or equiva-lent flashing. Termination spacing requirementsfrom the roof and from each other must be perFigure 19.
Vent and combustion air piping may be in-stalled in an existing chimney which is not inuse provided that:
a. Both the exhaust vent and air intake runthe length of the chimney.
b. The top of the chimney is sealed andweatherproofed.
c. The termination clearances shown inFigure 19 are maintained.
d. No other gas fired appliances are ventedthrough the chimney.
Vent Freezing ProtectionTo prevent condensate icing over extendedruns of vent pipe exposed to temperatures
below freezing, i.e., installation within a pre-existing masonry chimney; the pipe must beinsulated with 1/2 inch thick sponge rubberinsulation, such as an Armaflex-type or equiva-lent.
For extremely cold climates or for conditions ofshort furnace cycles (i.e. set back thermostatconditions) the last three feet of vent pipe canbe reduced one nominal pipe size provided thatthe total vent length is at least 15 feet in lengthand the vent is sized in accordance with theventing requirements (Table 4) before this re-duction is applied. (Example: 3" to 2-1/2") Smallervent pipes are less susceptible to freezing, butmust not be excessively restrictive.
Concentric Vent TerminationA concentric vent termination is approved foruse with these furnaces. The kit part number islisted in Table 13. For proper installation of theconcentric vent termination, follow the installa-tion instructions provided with that kit.
DRAINAGE OF CONDENSATE FROMFURNACE
! WARNING:The condensate produced by the furnacemust be drained. Do not connect a watersupply to the drainage hose of thefurnace.
NOTE: The condensate drain should be pro-tected from freezing when in unheated spaces.
CombustionAir
Intake
Elbow
ExhaustVent
Exhaust
Plumbing VentRoof Boot(Typ. Both Pipes)
A
A
1"
18" Min.36" Max.
Figure 19. Vertical Vent Termination
A= 12" Above Roof or Snow Accumulation Level
Figure 17. Alternate HorizontalVent Installation
OutsideWall
Support
Vent Configuration toProvide 12" Minimumheight above Snow Level.
1/2" ArmaflexInsulation orEquivalent(if required)
12" AboveNormallyExpectedSnowLevel
12" Min.19" Max.
19
The condensate drainage system is internal tothe furnace. The drain may exit either the rightor left side of the furnace cabinet. For a right sidedrain, simply extend the tubing out of the 7/8"hole in the cabinet (See Figure 20).
For a left side drain follow the steps below:1. Loosen the clamp on the soft exit tube
(see Figure 20.)2. Rotate the soft exit tube (counter clock-
wise, 180° upflow models; clockwise 90°downflow models.)
3. Re-tighten the clamp. MAKE SURECLAMP IS TIGHT TO AVOID LEAKAGEOF CONDENSATE.
4. Route the tubing out of the 7/8" hole located8 inches up from the bottom furnace.
The condensate should drain from the plasticcollector box (location A in Figure 20) as dropletsor a small stream. If you notice the furnace hasoperated for more than 5 minutes without drainingor the red status light on the control board ispulsing a 2-blink code follow the steps below.
1. Remove the collector box soft tube atlocation A in Figure 20 and insure the exitfrom the collector box is clear of anydebris or obstructions.
2. Replace this tube and insure the fit to theheader spout is air tight. Air will be drawn intothe header if this connection is not tight.
3. Check other tube connections along thedrain system. Insure that all are air tight.
NOTE: Industry research studies indicate thatwhen condensate is routed to an active drain,household detergents, etc., buffer its acidity. Ifthe drain is not actively used or if codes require,
8"
Left SideDrain
"HARD" JDrain Tube
Clamp(Loosen For Step 1)(Retighten for Step 3)
Route to floor drain....ORRoute to condensatepump. Keep downwardslope.
Collector Box
A
Rotate clockwise (Step 2)
Figure 20. Furnace with Condensate Drain Trap Assembly
8"
Left SideDrain
"HARD" JDrain Tube
Clamp(Loosen For Step 1)(Retighten for Step 3)
Route to floor drain....ORRoute to condensatepump. Keep downwardslope.
Collector Box
A
Rotate counterclockwise (Step 2)
obtain a neutralizer kit (usually contains lime-stone). Proper drains and connections to thecondensate tubing are required as NORDYNEcannot be held responsible for water leakagewhich occurs due to loose hose connectionsor improperly sealed drain line pipes.
GAS SUPPLY AND PIPING
GeneralThis furnace is equipped for either left or rightside gas entry. Typical gas service hook-upsare shown in Figure 21. When making the gasconnection provide clearance between thegas supply line and the entry hole in the furnacecasing to avoid unwanted noise and/or dam-age to the furnace.
All gas piping must be installed in compliancewith local codes and utility regulations. Somelocal regulations require the installation of amanual main shut-off valve and ground jointunion external to the furnace. The shut-offvalve should be readily accessible for serviceand/or emergency use. Consult the local utilityor gas supplier for additional requirementsregarding placement of the manual main gasshut-off. In the absence of local codes, the gasline installation must comply with the provi-sions stated in the Federal Manufactured HomeStandard (H.U.D Title 24, part 280 and theNational Fuel Gas Code (ANSI Z223.1/NFPA-54) or (CAN/CGA B149) installation codes.
A drip leg should be installed in the verticalpipe run to the unit. Table 8 lists gas flowcapacities for standard pipe sizes as a func-tion of length in typical applications based onnominal pressure drop in the line.
20
Typical Left Side Entry - Upflow
Some UtilitiesRequire Shut-
Off Valve to be 4 to 5 feetAbove Floor
Denotes field-provided andinstalledcomponents.
Burner ViewportRoll-Out Limit
Automatic Gas Valve(with manual shut-off)
BurnerAssembly
Ground JointUnion
Some UtilitiesRequire Shut-Off Valve to be 4 to 5 feetAbove Floor
Denotes field-provided andinstalledcomponents.
Burner Viewport
Automatic Gas Valve(with manual shut-off)
BurnerAssembly
Ground JointUnion
Roll-Out Limit
Typical Right Side Entry - Downflow
Figure 21. Typical Gas Service Connection
water column), the furnace must be discon-nected from the gas supply piping system toprevent damage to the gas control valve.
If the test pressure is less than or equal to1/2 psig (14 in. water column), the furnace mustbe isolated from the gas supply line by closingthe manual shut-off valve.
Leak CheckAfter the gas piping to the furnace is complete,all connections must be tested for gas leaks.To check for leaks use only a soap and watersolution or other approved method.
High Altitude DerateThe nameplate input rating for the furnacesapply for elevations up to 2,000 feet (610m)above sea level. For elevations over 2,000feet, reduce the input by 4% for each 1,000 feetabove sea level. For example, a furnace ap-plied at an elevation of 5,000 feet should bederated by 20%. See Table 9 describing thecorrect orifice for derate.
NOTE: For Canadian high altitude (2,000 to4,500 ft.), simply reduce the gas manifoldpressure to 2.8" WC for natural gas and 8.5"WC for LP gas without changing the orifices.
NOTE: The density of air decreases withincreasing elevation above sea level. Thisreduces the quantity of combustion air drawninto the furnace under normal operation andrequires the unit be derated by using smallergas orifices or lower manifold pressure.
NOTE: Gas piping must not be run in orthrough air ducts, chimneys, gas vents,elevator shafts, etc.
Compounds used on threaded joints of gaspiping must be resistant to the actions ofliquefied petroleum gases.
The main manual gas valve and main powerdisconnect to the furnace must be prop-erly labeled by the installer in case emer-gency shutdown is required.
! CAUTION:Do not use matches, lighters, candles,or other sources of open flame to checkfor gas leaks.
NOTE: When pressure testing gas supplylines at pressures greater than 1/2 psig (14 in.
Table 8. Capacity of Black Iron Gas Pipe (cu. ft. per hour) for Natural Gas
(specific gravity = .60)
NOMINAL LENGTH OF PIPE RUNBLACK IRON (feet)
PIPE DIAMETER(in.) 10 20 30 40 50 60 70 801/2 130 90 75 65 55 50 45 403/4 280 190 150 130 115 105 95 901 520 350 285 245 215 195 180 170
1 1/4 1050 730 590 500 440 400 370 3501 1/2 1600 1100 890 760 670 610 560 530
CAPACITY OF BLACK IRON GAS PIPE (CU. FT. PER HOUR)FOR NATURAL GAS (SPECIFIC GRAVITY - 0.60)
The cubic feet per hour listed in the table above must be greater thanthe cubic feet per hour of gas flow required by the furnace.
To determine the cubic feet per hour of gas flow required by thefurnace, divide the input rate of the furnace by the heating value of thegas:
Cubic Feet Input To Furnace (Btu/hr)Per Hour Required Heating Value of Gas (Btu/Cu. Ft.)=
21
CONVERSIONThis furnace can be converted from the factory-equipped gas to either natural gas (for LP gasready models), or LP gas (for natural gas readymodels). Conversions must be made by quali-fied service personnel, using only factory autho-rized or approved parts. The required conver-sion orifices are supplied with the furnace.
! WARNING:DO NOT REMOVE OR DEFACE THEORIGINAL RATING PLATE.
! CAUTION:The gas supply shall be shut off prior todisconnecting the electrical power,before proceeding with the conversion.
To Turn Off Fuel Supply to the Appliance:
1. Set the room thermostat to “OFF” or itslowest temperature setting.
2. Turn OFF the main gas supply to theappliance at the manual valve, outside ofthe appliance casing.
3. Remove the control access panel / lou-vered door.
EXAMPLE 1
Elevation 3,890 feetType of gas NaturalFurnace model M2RC-100A-16-BNOrifice as shipped #45 Drill
What burner orifices are needed?
The required input for 3890 feet is 84,000Btuh or 16% less than the sea level ratingof 100,000 Btuh.
See Table 8 for natural gas, find the FurnaceModel Number and follow across the table forthe elevation 2000-4000 column. From thetable, choose a #46 orifice. Install a #46 orificein every burner and check the firing rate per theVERIFYING AND ADJUSTING FIRING RATEsection. The firing rate in this example must notexceed 84,000 Btuh.
EXAMPLE 2
Elevation 5,500 feetType of gas PropaneFurnace model M2RC-100A-16-BNOrifice in Natural to LP Conversion Kit # 55 drill
What burner orifices are needed?
The required input for 5500 feet is 76,000Btuh or 24% less than the sea level ratingof 100,000 Btuh.
See Table 8 for LP gas, find the Furnace ModelNumber and follow across the table for theelevation 4000-6000 column. From the table,choose a #56 orifice. Install a #56 orifice inevery burner and adjust the manifold pressureto 10.0 inches water column. The firing rate inthis example must not exceed 76,000 Btuh.
4. Move the appliance gas valve lever/knobto the “OFF” position.
5. Turn OFF the electrical power to theappliance.
To Remove the Burner Assembly:
1. Follow the instructions “To Turn Off theFuel Supply to the Appliance.”
2. Disconnect the flame sensor wire fromthe burner box.
3. Disconnect the igniter wires at the 2 pinplug. This is a locking quick connect andboth sides of the lower section must bedepressed in order to be separated.
4. Remove the wires from the terminals ofthe gas valve.
5. Disconnect the rubber pressure tubesfrom the gas valve and the burner box.
6. Remove the burner access cover platefrom the burner box.
7. Remove supply gas piping from the gasvalve.
8. Carefully remove the burner assembly fas-teners and remove the burner assembly fromthe appliance. Keep the fasteners that wereremoved. Note that the burner box may havehooks near the top and on the right and lefthand sides. To remove this type of burnerbox, lift the burner box upwards and thenremove the box from the unit.
22
Figure 24. Typical Installation For SealedBurner Box With Access Cover Plate
Burner Orifices Gas
Manifold FlameObservation
Port
GasValve
AccessCoverPlate
BurnerBox
InletPressureTap Inlet
On/Off Lever
Figure 23. Burner Inspection
Table 9. Approximate Orifice Size for Natural and LP Gases
To Remove the Burner Orifices:
1. Remove the four (4) fasteners that securethe gas manifold to the burner box, asshown in Figure 24. Carefully remove thegas manifold assembly from the burnerbox. Note that the gas manifold assemblyconsists of the gas valve, the gas manifold,and the orifices.
2. Carefully remove the burner orifices fromthe gas manifold, as shown in Figure 24.
! CAUTION:Caution: Do not re-drill the burner orifices.If the orifice size must be changed, useonly new orifices.
Note: The size of the new orifices that willbe installed into the unit will depend uponthe type of conversion (sea level or highaltitude; natural gas or LP gas).
To Convert the Unit to the Alternate Gas
1. Remove the orifice bag from the manifoldof the unit.
2. Install the appropriate gas burner orificesinto the gas manifold. Remember if install-ing in the United States at altitudes above2,000 feet to install the proper orifices,shown in Table 6. When installing the neworifices, DO NOT use pipe joint com-pound on the orifice threads. Screw theorifices into the manifold by hand untilsnug to eliminate cross threading, thentighten with a wrench. Before installing anorifice, check the face or side of the orificefor the drill number to ensure that it is theappropriate size.
3. For the conversion to the alternate fuel,the gas valve regulator cap must beturned over, as shown in Figure 22. Youwill unscrew the cap and reinstall for yourinstallation. After reinstalling the cap, youwill be able to read "NAT" for the conver-sion to natural gas or "LP for the conver-sion to LP gas.
* can be N or L
Nat LP Nat LP Nat LP Nat LP Nat LP060A-16-B(*) 60,000 4 49 56 49 56 50 57 50 57 51 58080A-16-B(*) 80,000 4 45 55 46 55 49 56 49 56 50 57100A-16-B(*) 100,000 5 45 55 46 55 49 56 49 56 50 57
Furnace Model Number
M2R(C,L) -
Furnace RatingPlate Input
(Btuh)
No. ofBurners
Elevation0 - 2000
Elevation2000-4000
Elevation4000-6000
Elevation6000-8000
Elevation8000-10000
Figure 22. Convertible PressureRegulator Cap
PRESSURE REGULATOR CAP
M11678
NAT N
AT
L
P
L
P
NAT N
AT
OR
OTHER SIDEOF CAP
HoneywellValve
23
Reinstalling the Burner Assembly:
1. Reinstall the gas manifold assembly tothe burner box with the four (4) fasteners,which were removed earlier.
2. Carefully reinstall the burner box into theunit. After installing the burner, inspectthe alignment of the burners with the heatexchanger tubes. The center of the burn-ers should be aligned with the center ofthe tubes.
3. Reconnect the gas piping to the gasvalve.
4. Reconnect the wires to the gas valveterminals.
5. Reconnect the rubber pressure tubes tothe gas valve and the burner box. Rein-stall the burner access cover plate.
6. Reconnect the igniter at the 2 positionplug.
7. Reconnect the flame sensor wire to theburner box.
Pressure Gauge Installation
NOTE: For natural gas installations, the in-coming gas line pressure at the gas valve inletmust be between 4.5” WC and 10.0” WC. ForLP gas installations, the incoming gas linepressure at the gas valve inlet must be be-tween 11.0” WC and 14.0” WC. This pressurecan be checked at the inlet end of the gas valveusing a pressure gauge or U-tube manometer,which must be installed according to themanufacturer’s supplied instructions.
LIGHTING AND ADJUSTMENT OFTHE APPLIANCE
1. Turn ON the gas at the manual valve,outside of the unit.
2. Check all gas connections for leaks witha soap and water solution. If the solutionbubbles there is a gas leak which must becorrected. Do NOT use an open flame tocheck for gas leaks.
3. Turn ON the electrical power to the appli-ance.
4. Move the gas valve lever/knob to the“ON” position. The lever/knob must bemoved to the end of its range of motion toinsure the valve is completely open. Useonly your hand to push in or turn the gascontrol valve. Never use tools.
5. Set the room thermostat to a point aboveroom temperature to begin the heatingcycle of the unit.
6. Check that the unit ignites and operatesproperly. Refer to the installation instruc-tions provided with your unit for the nor-mal operating sequence.
7. After the flame ignites, visually inspectthe burner assembly to ensure that theflame is drawn directly into the center ofthe heat exchanger tube, as shown inFigure 23. The end of the flame will be outof sight around the bend of the heatexchanger tube. In a properly adjustedburner assembly, the flame color shouldbe blue with some light yellow streaksnear the outer portions of the flame.
NOTE: Until all of the air is bled out of the gasline, the hot surface igniter may not ignite thegas. If the ignition control locks out, turn thethermostat to its lowest setting and wait oneminute then turn the thermostat to a pointabove room temperature and the igniter will tryagain to ignite the main burners. This processmay have to be repeated several times beforethe burners will ignite. Once the burners are lit,check all gas connections for leaks again withthe soap and water solution. If the solutionbubbles there is a gas leak which must becorrected. Do not use an open flame to checkfor gas leaks.
Adjusting the Manifold Pressure
The manifold pressure can be measured byinstalling a pressure gauge or U-tube ma-nometer to the outlet end of the gas valve asfollows:
1. With a 3/16” Allen wrench, remove themanifold pressure tap plug located on theoutlet side of the gas valve. Refer toFigure 3 for more details.
2. A fitting, which has a 1/8” NPT pipe threadthat is compatible with the pressure gaugeor U-tube manometer, must be installedat this point.
3. Install the pressure gauge or U-tube ma-nometer according to the manufacturer’ssupplied instructions.
4. Set the room thermostat to a point aboveroom temperature to start the furnace.
5. Allow the furnace to operate for three (3)minutes and then check the manifoldpressure.
6. Table 10 lists the appropriate manifoldpressures for both natural gas and pro-pane (LP) gas installations. For the typeof fuel and the altitude of your installation,
24
Figure 26. Low Voltage Field,Four-wire Heating/Cooling Applications
R C
Y G
W
A/C Condensing Unit
Condensing UnitControl Box
RoomThermostat
Flame Signal Light(Yellow)
Status Light(Red)
60 90 120
180Blower Off
Timing
TWIN
3 AmpFuse
COM
24 V
HU
M
Neutrals
Low VoltageConnections
4 15 26 3
7
8
9
4
5
6
1
2
3
EA
C
HU
M M1
M2
M3
HE
AT
L1
XF
MR
Unused Motor Leads
EA
C
R Y
G W
Connect R & W
ForHeating
Only
FIELD WIRING
NOTE: The "Y" terminal on the UTEC control board must be connected to the thermostatfor proper coolingmode operation.
CO
OL
Field Supplied Disconnect Within Sight of Furnace
Field SuppliedPanel Connector
Field SuppliedFused Service
Panel
Black (Hot)White (Neutral)Green or Bare
(Ground)
BlackWhite
BlackWhite
BlackWhite
Field Line VoltageWiring
Factory LineVoltage Wiring
Ground Ground Ground
Junction Box (may be internalor external to the furnace). Theseconnections can be made in thefield supplied disconnect at thefurnace.
Table 10. Manifold Pressures for Sea Level
Natural Gas
Propane (LP)
10.0Manifold Pressure for 0-2000 Feet Above Sea Level (In WC)
3.5
determine the required manifold pres-sure. For Canadian high altitude installa-tions, refer to the "High Altitude Derate"section for more details.
COMPLETING THE CONVERSION
1. Affix the gas valve conversion label foundin the package with the orifices to the unitrating plate.
2. Run the appliance through a completecycle to assure proper operation.
! CAUTION:To avoid electric shock, personalinjury, or death, turn off the power atthe disconnect or the main servicepanel before making any electricalconnections.
ELECTRICAL WIRING
GeneralElectrical connections must be made in accor-dance with all applicable local codes and ordi-nances, and with the current revision of theNational Electric Code (ANSI/NFPA 70).
For Canadian installations electrical connec-tions and grounding must be done in accor-dance with the current Canadian ElectricalCode (CSA C22.1 Part 1) and/or local codes.If any of the original wire as supplied with thefurnace must be replaced, it must be replaced
Figure 25. Line Voltage Field Wiring
with wire having a minimum temperature ratingof 105°C. Refer to the furnace nameplate andTable 8 for electrical requirements.
Line Voltage WiringThe line voltage (115 volt) to the furnace mustbe supplied from a dedicated branch circuitcontaining the correct fuse or circuit breakerfor the furnace. See Table 11. An electricalswitch should be readily accessible from andwithin sight of the furnace. See the WiringDiagram label in the furnace for more details.
The furnace cabinet must have an uninter-rupted, unbroken ground to minimize injuryshould an electrical fault condition occur. Thecontrols used in this furnace require an earthground to operate properly. Acceptable meth-ods for grounding are electrical wire or conduitapproved for electrical ground service. Do notuse gas piping as an electrical ground.
25
Table 11. Electrical Data
* Time-delay fuses or HACR-type circuit breakers are required.
Figure 27. Ventilation Bracket
VentilAireBracket
NOTE: Proper line voltage polarity must bemaintained in order for the control system tooperate correctly. Verify that the incomingneutral line is connected to the white wire andthe incoming "hot" line is connected to the blackwire in the furnace junction box. The furnacewill not operate unless polarity and ground areproperly connected. See Figure 25.
! CAUTION:Label all wires prior to disconnectionwhen servicing controls. Wiring errorscan cause improper and dangerousoperation.
Verify proper operation after servicing.
! ATTENTION:Lors des opérations d'entretien descommandes, étiqueter tous les filesavant des les déconnecter. Toute erreurde câblage peut être une source dedanger et de panne.
S'assurer du bon fonctionnement del'appareil après tout entretien.
Low Voltage WiringInstall the thermostat per the manufacturer'sinstructions. The low voltage (24 volt) connec-tions from the thermostat are made at theterminal strip on the control board in the fur-nace. See Figure 26 for the proper connections
for heating only (two-wire) and heating/cooling(four-wire) applications. The recommendedminimum wire gauge for thermostat wiring isshown in Table 11.
The thermostat must not be installed on anoutside wall or any other location where itsoperation may be adversely affected. Adverseaffects include radiant loading from fireplaces,sunlight, or lighting fixtures, and convectiveloading from warm air registers or electricalappliances.
To check the heat anticipator setting either:
1. Add the current draw of the system com-ponents; or
2. Measure the current flow on the thermo-stat R-W circuit after the circulating blowermotor has started.
Set the heat anticipator according to the ther-mostat manufacturer's instructions for heatanticipator settings.
Furnace Cabinet Nominal Maximum Minimum Maximum Minimum MaximumInput Width Electrical Operating Operating Furnace Wire Fuse or Circuit(Btuh) (in.) Supply Voltage Voltage Amperes Gauge Breaker Amps*
60,000 19.75 115-60-1 127 103 9.7 14 1580,000 19.75 115-60-1 127 103 9.7 14 15
100,000 19.75 115-60-1 127 103 9.7 14 15
Thermostat Wire GaugeRecommended Thermostat Wire Length
2-wire (heating) 4 or 5-wire (cooling)
24222018
55 ft.90 ft.
140 ft.225 ft.
25 ft.45 ft.70 ft.
110 ft.
26
VENTILATION
Ventilation must be provided for homes built toHUD Manufactured Homes Safety and Con-struction Standards. This ventilation can besupplied by the VentilAire III or VentilAire IVaccessories (see Table 13). Alternate meansto provide the ventilation air must meet therequirements of all applicable local and federalcodes.
For downflow models, a bracket is suppliedwith the furnaces to allow the use of the VentilAireIII or VentilAire IV accessories. The bracket isinstalled on the right hand side at the top of thecabinet, as shown in Figure 27. The bracketcan be fastened using the self-drilling screwssupplied with the unit.
For upflow models, the means to provide therequired ventilation must be incorporated intothe upflow furnace base or the return airductwork to the furnace.
For installation of the VentilAire III or IV, followthe instructions provided with the VentilAire kit.
START-UP AND ADJUSTMENTSGeneralPrior to start-up, verify that:
1. The line voltage power leads are securelyconnected, that the polarity of the con-nections is correct, and that the furnaceis properly grounded.
2. The thermostat wires (R, W, Y, and G) aresecurely connected to the correct leadson the terminal strip of the circuit board.
3. The natural gas line service pressure mustnot exceed 10.0 in. water column (0.36psig), and must not be less than 4.5 in. watercolumn (0.16 psig). For LP gas the lineservice pressure must not exceed 14 in.water column (0.51 psig), and must not beless than 11.0 in. W.C. (0.40 psig).
4. The roll-out and vent safety manual resetswitches are closed. If necessary, pressthe red button to reset a switch. SeeFigure 31 for location. DO NOT install ajumper wire across a switch to defeat itsfunction. If a switch reopens on start-up,DO NOT reset the switch without identi-fying and correcting the fault conditionwhich caused the switch to trip.
5. The blower door is in place, closing thedoor switch in the line voltage circuit.
6. The gas line has been purged and allconnections are leak tight.
Start-Up Procedure1. Set the thermostat to the lowest setting.
2. Close the disconnect(s) to provide linevoltage to the furnace.
3. Follow the procedures given on the oper-ating instructions label attached to thefurnace.
4. Set the thermostat above room tempera-ture and verify the sequence of operation.(See the SEQUENCE OF OPERATION.)
5. After the furnace has run for approximatelyfive minutes, set the thermostat below roomtemperature and verify steps 9 - 11 of theSEQUENCE OF OPERATION.
Shut Down ProcedureIn the event that the furnace must be shut down,follow this procedure:
1. Set the room thermostat to "OFF" or itslowest temperature setting.
2. Turn OFF the main gas supply to theappliance at the manual valve outside ofthe appliance casing.
3. Remove the control access panel / lou-vered door.
4. Move the appliance gas valve lever/knobto the “OFF” position.
5. Turn OFF the electrical power to theappliance.
Verifying and Adjusting Firing RateThe firing rate must be verified for each instal-lation to prevent over-firing the furnace.
NOTE: The firing rate must not exceed therate shown on the furnace rating plate. Ataltitudes above 2000 ft. it must not exceedthat on the rating plate less 4% for each1000 ft.
Use the following procedure to determine thefiring rate:
1. Shut off all other gas fired appliances.
27
TIME FOR TIME FORONE REVOLUTION ONE REVOLUTION
(SECONDS) 1 5 10 (SECONDS) 1 5 1024 150 750 1500 80 45 225 45026 138 692 1385 82 44 220 43928 129 643 1286 84 43 214 42930 120 600 1200 86 42 209 41932 113 563 1125 88 41 205 40934 106 529 1059 90 40 200 40036 100 500 1000 92 39 196 39138 95 474 947 94 38 191 38340 90 450 900 96 38 188 37542 86 429 857 98 37 184 36744 82 409 818 100 36 180 36046 78 391 783 102 35 176 35348 75 375 750 104 35 173 34650 72 360 720 106 34 170 34052 69 346 692 108 33 167 33354 67 333 667 110 33 164 32756 64 321 643 112 32 161 32158 62 310 621 114 32 158 31660 60 300 600 116 31 155 31062 58 290 581 118 31 153 30564 56 281 563 120 30 150 300
GAS FLOW RATE (CUBIC FEET PER HOUR)
CUBIC FEET PER REVOLUTION OF METER
CUBIC FEET PER REVOLUTION OF METER
Table 12. Gas Flow Rate
R C
Y G
W
Flame Signal Light (Yellow)
60 90 120
180
TWIN
3 Amp FuseCOM
24 V
HU
M
Neutrals
4 1
5 2
6 3
7
8
9
4
5
6
1
2
3
EA
C
HU
M
M1
M2
M3
CO
OL
HE
AT L1
XF
MR
Unused Motor Leads
EA
C
Electronic Air Tap(.5A@ 120 VAC)
StatusLight (Red)
Humidifier Tap(.5A@ 120 VAC)
ConnectNeutralLead of
ElectronicAir Cleaner
and/or HumidifierHere.
Common Leads
Blower OffTiming
These motor speed taps arenot used for two-stage models
Figure 28. Blower Speed Tap Location
2. Start the furnace and allow it to run for atleast three minutes.
3. Measure the time (in seconds) required forthe gas meter to complete one revolution.
4. Convert the time per revolution to cubicfeet of gas per hour using Table 12.
5. Multiply the gas flow rate in cubic feet perhour by the heating value of the gas in Btuper cubic foot to obtain the firing rate inBtuh. Example:• Time for 1 revolution of a gas meter
with a 1 cubic foot dial = 40 seconds.• From Table 11 read 90 cubic feet per
hour of gas.• Heating value of the gas (obtained
from gas supplier) = 1040 Btu percubic foot.
• Firing rate = 1040 x 90 = 93,600 Btuh.
6. Relatively small adjustments to the firingrate can be made by adjusting the gasmanifold pressure.
7. See the "High Altitude Derate" section foradditional information on firing rate atelevations above 2000 ft.
The gas valve regulator is set at a nominalvalue of 3.5 in. water column for use withnatural gas. The manifold pressure must beset at 10.0 in. water column for use with LP gas.To adjust the manifold pressure, remove theregulator cap and turn the adjusting screw
clockwise to increase pressure or counter-clockwise to reduce pressure. Replace theregulator cap after adjustments are complete.
Verifying and Adjusting Temperature Rise
Verify that the temperature rise through thefurnace is within the range specified on thefurnace rating plate. Temperature rises out-side the specified range could result in prema-ture heat exchanger failure.
Place thermometers in the return and supplyair stream as close to the furnace as possible.The thermometer on the supply air side mustbe shielded from direct radiation from the heatexchanger to avoid false readings. Adjust all
28
registers and duct dampers to the desiredposition and run the furnace for fifteen minutesbefore taking any temperature readings. Thetemperature rise is the difference between thesupply and return air temperatures.
For typical duct systems, the temperature risewill fall within the range specified on the ratingplate with the blower speed at the factoryrecommended setting. If the temperature risemeasured is outside the range specified, it maybe necessary to change the blower speed.Lower blower speeds will increase the tem-perature rise and higher blower speeds willdecrease the temperature rise.
The furnace is equipped with a multispeedmotor. Heating and cooling speed selection ismade by moving the leads on the integratedcontrol board located in the furnace. The wiringdiagram on the furnace and Figure 28 show thespeed taps for adjusting motor speed.
If it is desired that the blower operate at thesame speed for heating and cooling, tape offthe terminal of the unused blower wire. Installthe jumper wire, found in the plastic instructionbag, across the HEAT and COOL taps on thecontrol board. Reconnect the desired blowertap to the piggyback quick connect.
The blower control is designed to start thecirculating air blower 30 seconds after the gasvalve is opened. The blower control is factorywired to turn the blower motor off 120 secondsafter the gas valve is closed. This timing can bechanged using the BLOWER OFF timing switchopposite the terminal block on the control board(See Figure 28).
Verifying Burner Operation
To verify operation of the burners, make surethat the blower compartment door is in placeand that there is power to the furnace. Set thethermostat above room temperature and ob-serve the ignition sequence. The flame can beobserved through the small clear window onthe burner box. The burner flame should carryover between all burners. The flames shouldbe blue, without yellow tips. Flames shouldextend from each burner without lifting, curling,or floating. After verifying ignition, set the ther-mostat below room temperature and verify thatthe burner flame extinguishes completely.
Verifying Operation of the Supply AirLimit SwitchTo verify operation of the supply air limit switch,make sure that the blower door is in place and that
there is power to the furnace. Completely blockthe return airflow to the furnace by installing aclose-off plate in place of or upstream of thefilter(s). Set the thermostat above room tem-perature and verify that the Sequence of Opera-tion is as described in these instructions. Thesupply air limit switch should function to turn offthe gas valve within approximately five minutes.The circulating air and combustion blowersshould continue to run when the supply air limitswitch opens. Remove the close-off plate imme-diately after the supply air limit switch opens. Ifthe furnace operates for more than five minuteswith no return air, set the thermostat below roomtemperature, shut off the power to the furnace,and replace the supply air limit switch.
DESCRIPTION OF COMPONENTS
Figure 31 shows the location of each of thefunctional components described below. Ifany component of the furnace must be re-placed, use only factory authorized replace-ment parts. Contact your distributor for theapproved replacement parts.
Flame Sensor – The flame sensor acts toprove that flame has carried over from theigniter to the opposite end burner. If no flameis sensed, the furnace will be shut downautomatically.
Gas Valve – The gas valve controls the flowof gas to the burners. When the gas valve isenergized it automatically opens and regu-lates the gas pressure in the manifold.
Pressure Switch – The pressure switch veri-fies that the inducer is drawing the combustiongases through the heat exchanger. It alsosenses a blocked condensate drain condition.
Vent Pressure Switch (Downflow modelsonly) – The vent pressure switch reacts toblockage in the vent or combustion air piping.
Supply Air Limit Switch – The supply air limitswitch prevents the air temperature leavingthe furnace from exceeding the maximumoutlet air temperature.
Vent Safety Switch – The vent safety switchshuts the furnace down if the outlet flue gastemperature increases above 160°F. Thisswitch protects the plastic flue system and theinducer from over-temperature conditions.
29
Flame Roll-Out Switch – This switch pro-vides flame roll-out protection to the furnaceand combustion air inlet pipe.
MAINTENANCE
It is recommended that the furnace be checkedyearly. At a minimum, this check should includethe following items:
! WARNING:To avoid electric shock, personal injury,or death, turn off the power at thedisconnect or the main service panelbefore performing any maintenance.
! WARNING:Holes in the vent pipe or heat exchangercan cause products of combustion toenter the occupied space. Replace thevent pipe or heat exchanger if leaks arefound. Failure to prevent products ofcombustion from being circulated into theoccupied space can crate potentiallyhazardous conditions, including carbonmonoxide poisoning, that could result inpersonal injury or death.
Combustion Air and Vent System
Check the combustion air and vent pipe toensure that it is not damaged, corroded orblocked by debris. Any damaged section ofvent pipe must be replaced, and any obstruc-tion or blockage must be removed prior tooperating the furnace.
Air Filter(s)
An air filter is supplied with the furnace asshipped from the factory. Filters should bechanged or cleaned monthly during the heatingseason. New or newly renovated homes mayrequire more frequent changing until the con-struction dust has been removed.
For the upflow model, the air filter is locatedunderneath the blower in the blower compart-ment. To remove the filter, first remove thelower door. Then, slide the filter backwards untilthe edge of the filter clears the front flange of the
furnace. Lift the filter up over the flange and thenremove. Reinstall the filter in the reverse man-ner. Ensure that the filter is centered over thereturn opening of the furnace, and is capturedby the fastener at the rear of the furnace.
For the downflow model, the filter is at the top ofthe furnace. The filter can be removed by liftingthe filter upwards and out of the opening. Rein-stall the filter in the reverse manner. Ensure thatthe filter is securely held by the braces on eitherside of the return air opening.
! WARNING:Never operate the furnace without a filterin place. Dust and lint in the return air canbuild up on internal components,resulting in loss of efficiency, equipmentdamage, and possible fire.
LubricationThe bearings in the circulating air blower mo-tors are pre-lubricated and sealed at the fac-tory. No further oiling of the bearings is re-quired for the life of the motor.
Condensate Drain AssemblyBe sure the condensate lines are free and open(i.e. avoid kinking hoses). Also make sure allhose clamps are tight to avoid drawing air intothe system.
Blower CompartmentThe blower compartment should be cleanedmonthly during the heating and cooling sea-sons to remove any dirt and lint that may haveaccumulated in the compartment or on theblower and motor. Dirt and lint can createexcessive loads on the motor resulting inhigher than normal operating temperaturesand shortened service life.
Heat Exchanger and Burner MaintenanceThe furnace should operate for many yearswithout excessive soot buildup in the fluepassageways, however, the flue passage-ways, the vent system, and the burners shouldbe inspected and cleaned (if required) by aqualified service technician annually to ensurecontinued safe operation. Particular attentionmust be given to identify deterioration fromcorrosion or other sources.
30
SYSTEM OPERATIONINFORMATION
GeneralProper maintenance is most important toachieve the best performance from a furnace.Follow these instructions for years of safe,trouble free operation.
• Do not place combustible materials on oragainst the furnace cabinet or the vent pipe.
• Do not store gasoline or any otherflammable vapors and liquids in the vicinityof the furnace.
• Change or replace the air filters monthlyduring any period when the circulatingblower is operating regularly.
• Always replace the doors on the furnaceafter servicing. Do not operate the furnacewithout all doors and covers in place.
• Avoid operating the furnace when windowsand doors are open.
• Be sure that the thermostat is properlyinstalled and is not being affected bydrafts or heat from lamps or otherappliances.
Sequence of OperationOperating sequences for the heating, cooling,and fan modes are described below. Refer tothe wiring diagrams (Figures 31 and 32) andthe low voltage field wiring diagram (Figure 26)for more details.
Heating Mode:1. On a call for heat the thermostat closes,
applying 24 VAC to the W terminal on thecontrol board.
2. The control board checks for continuityon the 24 VAC limit control circuit (over-temperature limit switch, flame rolloutswitches and blocked vent switch in se-ries). If an open limit is detected thecontrol board will energize the inducerand the conditioned air blower. All othersystem functions will be inoperable untilthe limit circuit closes. While the limit isopen, the red LED will pulse at a rate of 1blink per unit time.
3. The furnace control checks for continuityacross the pressure switch (24 VAC). Ifthe pressure switch is closed the heat
mode sequence will not continue. If itremains closed for 10 seconds the redLED will blink 3 times repetitively until thefault condition clears.
4. The inducer is energized.5. The pressure switch will close. If the
pressure switch does not close after 10seconds the fault LED will blink 2 timesrepetitively and the inducer will continue torun until the switch is closed.
6. The inducer will pre-purge for 30 secondsand then the igniter will start its warm-upas follows:Initial Power up: After 30 seconds ofigniter warm-up the gas valve (24 VAC)will then open. The igniter circuit will stayenergized for 3 seconds after the gasvalve opens.After Initial Power up: The control has aprogrammed adaptive ignition featurewhich varies the warm-up period as fol-lows: If ignition is successful the warm-upis reduced by 3-seconds on each subse-quent call for heat until ignition failureoccurs. Upon ignition failure, the warm-upis increased by 3-seconds on the next try.If successful, the timing remains fixed atthis level. In general, whenever ignitionfailure occurs the warm-up interval isincreased by 3-seconds on the next try.And if successful, it remains there. Mini-mum and maximum warm-up time limitsare set at 6 and 54-seconds, respec-tively.
7. The furnace control must prove flame viathe flame sensor 5 seconds after the gasvalve opens. If flame is sensed, all burn-ers are on and the igniter cools off. If noflame is sensed, the gas valve closesimmediately and the inducer continues torun. A second trial for ignition (step 6)begins if no flame is sensed. On the fifthtry for ignition, the furnace control is lockedout and the red LED will blink 4 timesrepetitively. The thermostat must beopened for at least ten seconds to resetthe furnace control after a lock out. Oth-erwise, the furnace will attempt anotherignition sequence in 1 hour.
8. The furnace control energizes the circu-lating air blower on the heating speed 30seconds after the gas valve circuit isenergized .
9. When the thermostat has been satisfied,gas valve is de-energized.
10. The inducer is de-energized after a 30-second postpurge.
31
Table 13. Accessory Kits
11. The furnace control keeps the circulatingair blower energized for 120 seconds(factory set) or 60, 90, or 180 seconds(field adjustable). (See Figure 28.)
12. Abnormal conditions: If a limit opens duringoperation, the inducer and circulating airblower continue to operate. The gas valveis de-energized immediately. The blowerscontinue to operate until the limit closes.When the limit closes the inducer blower isde-energized immediately. The circulatingair blower continues to operate for thespecified delay (factory set at 120 sec-onds).
Cooling Mode:1. On a call for cooling the thermostat closes,
applying 24 VAC to the G and Y terminalson the furnace control. This closes thecompressor contactor.
2. The furnace control energizes the circu-lating blower (115 VAC) on the coolingspeed.
3. When the thermostat is satisfied, the Gand Y terminals on the control board arede-energized opening the compressorcontactor.
4. The circulating air blower is de-energizedafter a 90-second delay.
Fan Mode:1. On a call for fan operation, the thermostat
applies 24 VAC to the G terminal on thefurnace control board.
2. The circulating air blower is energizedimmediately on the heating speed.
3. If the furnace is operated in the continu-ous ON position at the thermostat and isthen switched to AUTO, the circulatingblower will operate for a specified delay(factory set at 120 seconds).
Furnace Fails to OperateIf the furnace does not operate check thefollowing:1. Is the thermostat operating properly?2. Are the blower compartment door(s) in
place?3. Is the furnace disconnect closed?4. Has the circuit breaker tripped or the
control board fuse burned open?5. Is the gas turned on?6. Are any manual reset switches open?7. Is the filter dirty or plugged?8. Is the flame sensor coated? (Remove and
clean with emery cloth.)
FURNACE ACCESSORY KITS
If the furnace locks out after 5 attempts forignition, it will try again every hour if a call forheat remains. If the inducer and circulating airblowers are operating, and items 1 through 8have been checked, press the red reset but-ton on the vent safety switch. (See Figure 30.)If the furnace operates after depressing thereset button, contact a qualified service tech-nician to identify and repair the problem.
If furnace continues to not operate, depressthe red reset buttons on the flame roll-outswitch. If the furnace operates after depress-ing the reset button, contact a qualified servicetechnician to identify and repair the problem.
Kit Order Number
Fossil Fuel Kit 914762
A/C Coil Box 914958
Sloped Roof VentilAire III Kit 914098
Sloped Roof VentilAire IV Kit 914229
Soffit VentilAire Kit 917201
Concentric Vent Termination Kit (for horizontal and vertical venting)
904176 (3 Inch) 904177 (2 Inch)
Horizontal Exterior VentMounting Kit 2"PVC 902373
Mounting Kit 3"PVC 902375
Neutralizer Kit - All Models 902377
32
1 Manifold2 Flame Sensor (Not Shown)3 Gas Valve4 Roll-Out Limit Switch (155°F)5 Pressure Switch6 Control Board, Integrated7 Blower Door Switch8 Vent Safety Limit Switch (160°F)9 Transformer
10 Limit Switch11 Blower Assembly12 Inducer Blower (with gasket)13 J Trap Hard Tube14 In-Line Drain Assembly15 Burner Box Assembly (Nat. and LP Gas Ready)16 Header Outlet Box17 Cased Coil Wrapper18 Filter (18 5/8 x 26 1/2 x 1/4) (Not Shown)19 Attachment Bracket20 Turbulator (Not Shown)21 Coupling Neoprene22 Orifice, Inducer (Not Shown)23 Inshot Burner (Not Shown)24 Natural and LP Gas Orifice (Not Shown)25 Igniter (Not Shown)26 Heat Exchanger Assembly (Not Shown)27 Capacitor Assembly, 10 MFD, 370V (Not Shown)28 Blower Wheel CCW (Not Shown)29 Motor - 1/2 HP (4 Speed) (Not Shown)30 Access Doors, Set (Not Shown)
3
4
9
10
11
12
17
19
5
6
7
8
15
16
13
14
211
3
4
9
10
12
17
19
5
6
8
14
15
16
11
1
13
1 Manifold2 Flame Sensor (Not Shown)3 Gas Valve4 Roll-Out Limit Switch (155°F)5 Pressure Switch6 Integrated Control Board7 Blower Door Switch (Not Shown)8 Vent Safety Limit Switch (160°F)9 Transformer
10 Limit Switch11 Blower Assembly12 Inducer Blower (with gasket)13 J Trap Hard Tube14 In-Line Drain Assembly15 Burner Box Assembly16 Header Outlet Box17 Cased Coil Wrapper18 Filter (18 x 20 x 1) (Not Shown)19 VentilAire Bracket20 Attachment Bracket21 Turbulator (Not Shown)22 Auxillary Limit Switch (120°) (Not Shown)23 Inducer Orifice (Not Shown)24 Inshot Burner (Not Shown)25 Natural and LP Gas Orifice (Not Shown)26 Igniter (Not Shown)27 Heat Exchanger Assembly (Not Shown)28 Capacitor Assembly, 10 MFD, 370V (Not Shown)29 Blower Wheel CCW (Not Shown)30 Motor - 1/2 HP (Not Shown)31 Access Door (Not Shown)
Figure 30. Location of Major Components
Upflow Furnace
Downflow Furnace
33
IGNITOR
INDUCER
GAS
VALVE
SUPPLY AIRLIMIT SWITCH(ALL MODELS)
VENTSAFETYSWITCH
(ALL MODELS)
TRANSFORMER
FLAME SENSOR
C
GREEN
BLACKWHITE
BLUE BLUE
24 V 120 VO
RA
NG
E
BL
UE
BL
UE
YELLOWBROWN
RED
BLACK
WHITE
ORANGE
BLUE
BL
AC
K
OR
AN
GE
BLACK
RED
AIR CONDITIONERCONDENSING UNIT
BLACK
BLACK
BLOWER DOORSWITCH
R
WHITE
BLACK
WHITE W/ BLK STRIPES
BLK W/ WHITE STRIPES
WHITE (NEUTRAL)
BLACK 120V
GROUND
ROOM THERMOSTAT
3 OR 4 SPEED MOTOR
H
MHML
L
C
WH
ITE
RE
D
OR
AN
GE
BL
UE
BL
AC
KMOTORPLUG
1
2
3
4
5
6
BLACK
BLUE
FLAME ROLL-OUTSWITCH
(ALL MODELS)
VENTPRESSURE SWITCH(93+ MODELS ONLY)
PRESSURESWITCH
R
Y
G
W
C
Y
1801209060
THESE WIRES ARENOT PRESENTON 3 SPEED
MODELS
BLOWERDECK SWITCH
(SELECT MODELSONLY)
Legend
Field WiringFactory Wiring:
Low VoltageHigh Voltage
Power On
Limit Circuit Open or External Load On "W"
Pressure Switch Stuck Open
Pressure Switch Stuck Closed
Ignition Failure (Check Ground)
115 VAC & Neutral Reversed or no Ground
False Flame or Gas Valve Relay Shorted
ON
1 FLASH
2 FLASHES
3 FLASHES
4 FLASHES
5 FLASHES
Continuous
STATUSRED LIGHTFAULT CONDITION
Power Off
Low Flame Sensor Signal
Flame Present
ContinuousFlash
OFF
ON
FLAMEYELLOW
LIGHTFAULT CONDITION
Figure 31. Upflow and Downflow Furnace Wiring Diagram
If any of the original wire as supplied withthe furnace must be replaced, it must bereplaced with wiring material having atemperature rating of at least 105° C.Use copper conductors only.
WD #710062A
34
UNIT MODEL NUMBER _______________
Minimum Clearances per Table 3? _______
Electrical Connections tight? ____________
Line Voltage Polarity correct? ___________
Supply Voltage: ___________________ Volts
Blower Motor HP: _____________________
FUEL TYPE:
Natural Gas _____ LP/Propane _______
Gas Piping Connections leak-tested? _____
Gas Line Pressure: ___________________(in. water column, with furnace operating)Manifold Pressure: ____________________(in. water column, with furnace operating)Is there adequate fresh air supply forcombustion and ventilation? _____________
Furnace Input: _________________ (Btuh)
Supply Air Temperature: _________ (° F)
Return Air Temperature: _________ (° F)
Temperature Rise: ______________ (° F)
UNIT SERIAL NUMBER ________________
Are Flue Connections tight? _____________
Is there Proper Draft? _________________
Is Vent free from restrictions? ___________
Is the Filter(s) secured in place? _________
Is the Filter(s) clean? __________________
Has the Thermostat been calibrated? _____
Is the Thermostat level? ________________
Is the Heat Anticipator Setting correct? ____
Has the Owner's Information been reviewedwith the home-owner? _________________
Has the Literature Package been left nearthe furnace? _________________________
LOCATION ____________________ CITY __________________ STATE ____________
INSTALLER ___________________ CITY __________________ STATE ____________
INSTALLATION/PERFORMANCE CHECK LIST
35
¢708120i¤708120B
O'Fallon, MO
708120B (Replaces 708120A)
Specifications and illustrations subject to change withoutnotice and without incurring obligations. Printed in U.S.A.
(04/04)
