FOR MAXIMUM EFFICIENCY,FLEXIBILITY AND ECONOMY

THE TROUBLE-FREE METHOD OFINTERLINKING TWO OR MORE BOILERS

THE "C" TYPE NEUTRALIZERThe "C" type Neutralizer is designed for installing belowthe hot water cylinder, and can be supplied withadditional connections and capacity.This model can be used for systems with three or moreboilers. (Refer to installation instructions.)

A standard Neutralizer has nine 28mm diameterconnections.

THE "R" TYPE NEUTRALIZERThe "R" type Neutralizer is designed for wall mounting,adjacent to the hot water cylinder. The shape facilitatesthe fitting of neat pipework.

166 m

m

450 mm

220 mm

150 mm

200 m

mDUNSLEY

BOILER SYSTEMS

Fused switched spur

22mm 22mm

Cylinder thermostat m.o.r.

Orange

Sunvic SZ 2355 specialspring open motorised valve.Obtainable only fromDunsley Heat Ltd.

28mm

Anti-boil stat (1) b.o.r.

Yellow

9 way"R" typeneutralizer

Bathroom radiator

15mm

Anti-boil stat (2) m.o.r.

E

Spring closed m/valveInjector tee

22mm

BlueN

a.a.v.E

E

Pin

k

28mm regulatingvalve (gate)

Roomstat b.o.r.

Isolating switch

28mm 22 or 28mm

Honeywell ST699B10022 Channelprogrammer

Pipe stat m.o.r.set 60°c.

Group 2. Boiler or cooker. Space heating circuit Gas or oil fired boiler

900mm min22mm 22mm

This pipe must rise to high level(roof space), to generate gravity flow

The solid fuel cooker requires a heat soak, this is usually catered for by a conventional hot water cylinder.Unvented hot water cylinders do not providea heat soak when the cylinder stats switchesoff the zone valve.

or boiler

28mm

Time switch

Fused spur

Spring open m/valve

Spring closedm/valve

22mm

The 1st floor circuit must be able to dissipate the heat generated by the solid fuel cooker or boiler in the event of pump or electrical failure. Some of the rads must be live.

1st floor room stat b.o.r.

Honeywell ST699BProgrammer

15mm bypass

28mm

Cylinder stat b.o.r.

Unvented cylinder

Spring closedm/valve

The cylinder can beinstalled on any floor. Ground floor

heating

Springclosedm/valve

28mm

28mm

Ground floorRoom statb.o.r.

15mm

a.a.v.

m.o.r. statset 60°c

b.o.r. statset 87°c

Heat leakrad 15mm

A B C

E

ch1 ch2

DUNSLEY-BAKER NEUTRALIZER SYSTEM

Layout 1. / SP

Layout 2. Layout 3. / B89a Using a Mains Pressure Cylinder

LAYOUT OPTIONS FOR LINK-UP SYSTEMS

Layout 4. / 3 Layout 5. / B148

Layout 6. / B

a.a.v.

Relay

Bypass

Pump controlstat m.o.r.

1st floorRoom stat

1st floor spaceheating

Time switch

Ground floorRoom stat

n.c. m/valve with spst aux switch

Cylinder stat bor

Terminal

Rayburn 400 seriesoil fired cooker

Ground floorspace heating

Gas or oil fired boiler

n.c. m/valve withspst aux switch

For further information on system design, please contact us on Tel: (01484) 682635

22mm 22mm

Fused switched spur

Bathroom radiator

Cylinder thermostat m.o.r.

Orange

22mm

Sunvic SZ2355 special, spring open motorised valve

a.a.v.E

NBlue

YellowAnti-boil stat (1) b.o.r.Anti-boil stat (1) b.o.r.

11 way (R) type neautralizer11 way (R) type neautralizer28mm Regulating valve(gate)28mm Regulating valve(gate)

NE

NE

E

Anti-boil stat (2) m.o.r.

15mm

White

Pin

k

28mm28mm

E

Injector teeSpring closed m/valve

15 or 22 mmNE

Roomstat b.o.r.

Isolating Switch

28mm 28mm

22 or 28mm22 or 28mmPipe stat m.o.r.set 60°c

E

HoneywellST699B10022 channelprogrammer

N E

NE

Gas or oil fired boiler only.Hot water only A on B off C offHeating and hot water A on B on C off

Solid fuel boiler only.Heating and hot water A off B on C onHot water only or slumber A off B off C off

Solid fuel boiler with gas or oil fired boiler.Heating and hot water. A on B on C on

Anti-boil controlIn the event of an overheated situation developing, anti-boil stat (2) set at 85°c will make and switch on the space heating pump.If the space heating pump or the electricity should fail, anti-boil stat (1) set at 88°c will break and allow the spring open motorised valve to open, this will switch off the gas or oil filled boiler and open the cylinder circuit.

Refer to installation instructions for boiler classification.

Gas or oil fired boiler only.Hot water only A on B off C offHeating and hot water A on B on C off

Group 2. Boiler only.Heating and hot water A off B on C onHot water only or slumber A off B off C off

Group 1. Boiler only.Hot water only. A off B off C offHeating and hot water. A off B on C off

Anti-boil controlIn the event of an overheated situation developing, anti-boil stat (2) set at 85°c will make and switch on the space heating pump.If the space heating pump or the electricity should fail, anti-boil stat (1) set at 88°c will break and allow the spring open motorised valve to open, this will switch off the gas or oil filled boiler and open the cylinder circuit.

Refer to installation instructions for boiler classification.

Gas fired boiler. set 77°c Solid fuel

N L

With time and temperature controls.Group 3 and 4 boilers operate on demand only.

With time and temperature controls.Group 3 and 4 boilers operate on demand only.

The system layouts illustrated are a selection from our extensive range.Use in conjunction with the installation instructions supplied with the unit.For further information on system design, or for an A4 size detaileddrawing of a layout, please contact us on Tel: (01484) 682635.

Should the flow pipe rise up from the oil or gas boiler to the neutralizer only one vent will be required from the top of the neutralizer.

Group 2.Boiler orcooker.

Space heating circuit

Group 1.Boiler orcooker.

Gas or oilfired boiler

a.a.v.

A B

C

Low domestic hot water head.

The Hot Tube is in the lower half of the cylinder.(Hot water rises to the top).

22mm

D.P. fused isolator

C.W.S. Tank

DomesticHot water

Solar system filled with nontoxic antifreeze

Air valve

28mmControlpanel

Spring checkvalve

Expansionvessel

Filling point

HoneywellST699B 1002

Anti-boil statc/o. set 87°c

Roomstat b.o.r.

R-TypeNeutralizerR-TypeNeutralizer

Inj tee

22mm28mm Spring

openm/valve

Springopenm/valve

Cylinderstat m.o.r.

28mm pipesSpace heating

22mm

Pump

Live radiator(gravity flow)

15mm

PIPE STATMAKE ON RISESET @ 60°c

a.a.v.

Gas or Oil Boiler Solid Fuel Boiler

Key: N/C=normally openN/O=normally openA.A.V=automatic air valveM.O.R.=make on riseM.V. motorise valve

N/OTHIS PUMP HAS TO COME ONWHEN CYLINDER IS CALLINGFOR HOT WATER SO IT WILL HEATUP THE CYLINDER FROM OILBOILER OR SOLID FUEL BOILER

A.A.V.

N/C

Fused switched spur

22mm 22mm

Cylinder thermostat m.o.r.

Orange

Sunvic SZ 2355 specialspring open motorised valve.Obtainable only fromDunsley Heat Ltd.

28mm

Anti-boil stat (1) b.o.r.

Yellow

9 way"R" typeneutralizer

Bathroom radiator

15mm

Anti-boil stat (2) m.o.r.

E

Spring closed m/valveInjector tee

22mm

BlueN

a.a.v.E

E

Pin

k

28mm regulatingvalve (gate)

Roomstat b.o.r.

Isolating switch

28mm 22 or 28mm

Honeywell ST699B10022 Channelprogrammer

Pipe stat m.o.r.set 60°c.

Group 2. Boiler or cooker. Space heating circuit Gas or oil fired boiler

900mm min22mm 22mm

This pipe must rise to high level(roof space), to generate gravity flow

The solid fuel cooker requires a heat soak, this is usually catered for by a conventional hot water cylinder.Unvented hot water cylinders do not providea heat soak when the cylinder stats switchesoff the zone valve.

or boiler

28mm

Time switch

Fused spur

Spring open m/valve

Spring closedm/valve

22mm

The 1st floor circuit must be able to dissipate the heat generated by the solid fuel cooker or boiler in the event of pump or electrical failure. Some of the rads must be live.

1st floor room stat b.o.r.

Honeywell ST699BProgrammer

15mm bypass

28mm

Cylinder stat b.o.r.

Unvented cylinder

Spring closedm/valve

The cylinder can beinstalled on any floor. Ground floor

heating

Springclosedm/valve

28mm

28mm

Ground floorRoom statb.o.r.

15mm

a.a.v.

m.o.r. statset 60°c

b.o.r. statset 87°c

Heat leakrad 15mm

A B C

E

ch1 ch2

DUNSLEY-BAKER NEUTRALIZER SYSTEM

Layout 1. / SP

Layout 2. Layout 3. / B89a Using a Mains Pressure Cylinder

LAYOUT OPTIONS FOR LINK-UP SYSTEMS

Layout 4. / 3 Layout 5. / B148

Layout 6. / B

a.a.v.

Relay

Bypass

Pump controlstat m.o.r.

1st floorRoom stat

1st floor spaceheating

Time switch

Ground floorRoom stat

n.c. m/valve with spst aux switch

Cylinder stat bor

Terminal

Rayburn 400 seriesoil fired cooker

Ground floorspace heating

Gas or oil fired boiler

n.c. m/valve withspst aux switch

For further information on system design, please contact us on Tel: (01484) 682635

22mm 22mm

Fused switched spur

Bathroom radiator

Cylinder thermostat m.o.r.

Orange

22mm

Sunvic SZ2355 special, spring open motorised valve

a.a.v.E

NBlue

YellowAnti-boil stat (1) b.o.r.Anti-boil stat (1) b.o.r.

11 way (R) type neautralizer11 way (R) type neautralizer28mm Regulating valve(gate)28mm Regulating valve(gate)

NE

NE

E

Anti-boil stat (2) m.o.r.

15mm

White

Pin

k

28mm28mm

E

Injector teeSpring closed m/valve

15 or 22 mmNE

Roomstat b.o.r.

Isolating Switch

28mm 28mm

22 or 28mm22 or 28mmPipe stat m.o.r.set 60°c

E

HoneywellST699B10022 channelprogrammer

N E

NE

Gas or oil fired boiler only.Hot water only A on B off C offHeating and hot water A on B on C off

Solid fuel boiler only.Heating and hot water A off B on C onHot water only or slumber A off B off C off

Solid fuel boiler with gas or oil fired boiler.Heating and hot water. A on B on C on

Anti-boil controlIn the event of an overheated situation developing, anti-boil stat (2) set at 85°c will make and switch on the space heating pump.If the space heating pump or the electricity should fail, anti-boil stat (1) set at 88°c will break and allow the spring open motorised valve to open, this will switch off the gas or oil filled boiler and open the cylinder circuit.

Refer to installation instructions for boiler classification.

Gas or oil fired boiler only.Hot water only A on B off C offHeating and hot water A on B on C off

Group 2. Boiler only.Heating and hot water A off B on C onHot water only or slumber A off B off C off

Group 1. Boiler only.Hot water only. A off B off C offHeating and hot water. A off B on C off

Anti-boil controlIn the event of an overheated situation developing, anti-boil stat (2) set at 85°c will make and switch on the space heating pump.If the space heating pump or the electricity should fail, anti-boil stat (1) set at 88°c will break and allow the spring open motorised valve to open, this will switch off the gas or oil filled boiler and open the cylinder circuit.

Refer to installation instructions for boiler classification.

Gas fired boiler. set 77°c Solid fuel

N L

With time and temperature controls.Group 3 and 4 boilers operate on demand only.

With time and temperature controls.Group 3 and 4 boilers operate on demand only.

The system layouts illustrated are a selection from our extensive range.Use in conjunction with the installation instructions supplied with the unit.For further information on system design, or for an A4 size detaileddrawing of a layout, please contact us on Tel: (01484) 682635.

Should the flow pipe rise up from the oil or gas boiler to the neutralizer only one vent will be required from the top of the neutralizer.

Group 2.Boiler orcooker.

Space heating circuit

Group 1.Boiler orcooker.

Gas or oilfired boiler

a.a.v.

A B

C

Low domestic hot water head.

The Hot Tube is in the lower half of the cylinder.(Hot water rises to the top).

22mm

D.P. fused isolator

C.W.S. Tank

DomesticHot water

Solar system filled with nontoxic antifreeze

Air valve

28mmControlpanel

Spring checkvalve

Expansionvessel

Filling point

HoneywellST699B 1002

Anti-boil statc/o. set 87°c

Roomstat b.o.r.

R-TypeNeutralizerR-TypeNeutralizer

Inj tee

22mm28mm Spring

openm/valve

Springopenm/valve

Cylinderstat m.o.r.

28mm pipesSpace heating

22mm

Pump

Live radiator(gravity flow)

15mm

PIPE STATMAKE ON RISESET @ 60°c

a.a.v.

Gas or Oil Boiler Solid Fuel Boiler

Key: N/C=normally openN/O=normally openA.A.V=automatic air valveM.O.R.=make on riseM.V. motorise valve

N/OTHIS PUMP HAS TO COME ONWHEN CYLINDER IS CALLINGFOR HOT WATER SO IT WILL HEATUP THE CYLINDER FROM OILBOILER OR SOLID FUEL BOILER

A.A.V.

N/C

Gives a trouble free method of interlinking two or more boilersto give economy and flexibility

DUNSLEY-BAKER NEUTRALIZER SYSTEM

HISTORICAL NOTE

TECHNICAL DIFFICULTIES

DUNSLEY BAKER NEUTRALIZER

For a period during the late sixties early seventies there was a tendency to do away with the open fire by building up the opening and depending on one boiler source for heating the dwelling.In recent years the move has been to re-open the fireplace as an alternative source of heat and to give a focal point for the evening relaxation plus the advantage of good ventilation.With this has come the realisation that the open fire with high output boiler or a cooker with high output boiler would be very economical and versatile in use if it could be linked into the central heating system to supply, or assist to supply, the entire demand for heating and domestic hot water.

In principle the requirement to link two or more boilers into one heating system is relatively simple to arrange. In practice there are physical difficulties, possible dangers, and in many cases high financial cost to the householder.The difficulties lie in linking the boilers, so that one boiler when in operation does not supply the second boiler with hot water when it is not in operation. Attempts to link boilers in domestic situations have resulted in solutions which are either dangerous, unnecessarily complex, expensive or a combination of all three. Also in numerous systems an unacceptable degree of domestic upset is encountered during installation.

The use of a Dunsley Baker Neutralizer offers a neat solution to all of the problems highlighted above. The description 'Circuit Neutralizer' (also referred to as a neutralizing vessel or chamber) is intended to convey the fact that the neutralizer fixes the neutral point location within the system.The cold feed and open vent are both connected to the system at the neutralizing chamber and provided that both boilers are only connected through this point then pumped or gravity circuits connected to the chamber can have no hydraulic interaction.This means in effect that the pumped circuit from, say a gas or oil fired boiler will not induce flow through a solid fuel boiler via its gravity circuit. The solid fuel boiler will, however, feed hot water into the system, thus achieving the desired objective.

It must also be pointed out that whilst twoboilers connected as above is the most common mode ofsystem operation the Dunsley Baker Neutralizer Systemlends itself easily to cope with more than two boilers on theone system and with a multiplicity of circuits makingpossible effective joining for increased controllability.

Two comments with reference to location:1. In converting an existing system to a Dunsley BakerNeutralizer system most of the work takes place within thehot cupboard area, thus avoiding general disruption withinthe premises.2. Where the solid fuel appliances are on the same floor levelas the neutralizing vessel elevation of the neutralizer and hotwater cylinder would be necessary in order to achieve (A)venting and (B) gravity circulation.

The concept of enlarging the 'neutral point' to the volumebound physically by the welded construction of theneutralizing chamber is the distinctive feature of the systemand any configuration of pipework and componentsemploying this concept is referred to as a Dunsley BakerNeutralizer System, regardless of the number of boilers,pumps, circuits, etc.

The sketches show some of the many arrangementspossible in different circumstances where a Dunsley BakerNeutralizer System will facilitate the interlinking of domesticboilers and suggestions are also indicated of suitable controlsystems.We are continuing to produce updated information onsystem design and, therefore, welcome requests for adviceon situations which deviate from those described in thisbrochure.

The Dunsley Baker Neutralizer System is the invention ofJohn Baker. U.K. Patent no. 2113364, and is manufacturedand sold under licence in England, Scotland, Wales,Northern Ireland, Isle of Man and Channel Islesby Dunsley Heat Ltd., Fearnought,Holmfirth, Huddersfield, England, HD7 2TU.

Tel: 01484 682635 4 lines.

NEUTRALIZER LOCATION

DUNSLEY BAKER NEUTRALIZER SYSTEM

CONTINUED DEVELOPMENT

The Best of Both WorldsLink up with

DUNSLEY/BAKERNEUTRALIZER SYSTEM

Dunsley Heat Ltd, Bridge Mills, Huddersfield Road,Holmfirth, Huddersfield HD9 3TW

Tel: (01484) 682635 Fax: (01484) 688428email: sales@dunsleyheat.co.uk

Web Site: www.dunsleyheat.co.uk www.multifuelcookers.co.uk A/2

6151/2

3/0

7/0

9

All Dunsley Products aremanufactured in Great Britain