Water heater B 7 W/D 7 W · 2016-05-06 · Check combustion air fan. Check motor speed relay (2.5.8). Check connection to control unit (connections A11 and B1). Visit for more technical

® Eberspächer

J. EberspächerEberspächerstr. 24D-73730 Esslingen

Telefon (zentral)(0711) 9 39-00Telefax(0711) 9 39-05 00

25 1807 95 09 50. 03.1996 Modifications reserved. Printed in Germany. © Copyright J. Eberspächer C 27.

Troubleshooting and Repair Manual

Valid for heater versions

B 7 W

20 1673 05 00 00 – 12 Volt

D 7 W

25 1666 05 00 00 – 12 Volt 25 1807 05 00 00 – 12 Volt

25 1667 05 00 00 – 24 Volt

Contents page

In the event of faults, first check thefollowing points............................................. 2

Function and fault test.................................. 2 – 8

Control in heating operation......................... 9

Function sequence....................................... 10

Wiring diagrams.......................................... 11 – 14

Repair instructions....................................... 15 – 21

Measuring the fuel quantity ......................... 21, 22

New featuresin version 25 1807 05 00 00 – 12 Volt

• flame control PT 1000 in exhaust fitting

• new control unit

• spring-loaded overheating switch

• wiring diagram page 13, 14

Water heater B 7 W/D 7 W

Visit www.butlertechnik.com for more technical information and downloads.

www.butlertechnik.com

If the fault is not recognized by the control unit, see page 5 ofthe function and fault test.

Indicator

Does the function and fault display (flashing code) integrated inthe heating switch indicate a fault?

Identify the signal (flashing code) and rectify the fault accordingto the function and fault test, page 3 – 5.

If the operating element does not have a fault indicator, anindicator is then fitted to the control unit at the „Test/S”connection. An LED or an acoustic signal transmitter can beused as the indicator.Once the heater has been switched on, the indicator will showthe signals.See the function and fault Test on pages 3 – 5 for identifying thesignal (flashing code) and remedying the trouble.

Function and fault test

for 20 1673 05 00 00 – 12 Volt25 1666 05 00 00 – 12 Volt25 1667 05 00 00 – 24 Volt

for 25 1807 05 00 00 – 12 Volt

Does the function and fault display (flashing code) integrated inthe heating switch indicate a fault?

Identify the signal (flashing code) and rectify the fault accordingto the function and fault test, page 6 – 8.

A diagnosis unit (order no. 22 1512 89 00 00) can be connectedup instead of the timer (3.2.5 in wiring diagram) to indicatepossible faults.For instructions, please refer to the operating manual for thediagnosis unit. Troubleshooting (fault list and fault rectification)see function and fault test page 6 – 8.

Test

In the event of faults, first check the followingpoints:

• Fuel in the tank?

• Heater lever (water valve) properly in the „WARM” position?

• Fuses OK?

• Electrical lines, connectors, connections OK?

• Clogged combustion air line or exhaust line?

• Is the water pump running?

If not – check whether there is voltage at the motor?if so – replace the water pumpif not – replace the control unit

2

SwitchPositive

• Has the overheating switch triggered?

Press the middle raised knob of the rubber cover to unlock theoverheating switch located below.



01

23

45

67

89

1011

1213

Indi

catio

n

Sec

onds

Sig

nal

Cau

seR

emed

y

Sta

rt, h

eatin

g ph

ase

(tro

uble

-fre

e op

erat

ion)

Nor

mal

ope

ratio

n(t

roub

le-f

ree

oper

atio

n)

Del

ayed

shu

t-of

f, re

star

t(h

eate

r st

ill n

ot s

hut o

ff or

in th

e co

ntro

lin

terv

al w

hen

star

ted)

War

ning

: pow

er s

uppl

y(u

nder

volta

ge o

r ov

ervo

ltage

)

Ove

rhea

t(a

utom

atic

cut

out)

Fla

me

sens

or d

efec

tive

(sho

rt-c

ircui

t)

Fla

me

out L

o w

(fla

me

goes

out

by

itsel

fin

„Lo

w”

setti

ng)

Fla

me

out H

i g

h(f

lam

e go

es o

ut b

y its

elf

in „

Hig

h” s

ettin

g)

Hea

ter

still

not

shu

t off

Wat

er te

mpe

ratu

re s

till a

bove

the

trig

gerin

g po

int f

or th

e te

mpe

ratu

rese

nsor

(ap

prox

. 80

°C)

Tem

pera

ture

sen

sor

inte

rrup

tion

Fla

me

sens

or d

efec

tive

Insu

ffici

ent f

uel

Spe

ed o

f blo

wer

not

red

uced

Vap

our

lock

in th

e fu

el li

ne?

Con

trol

uni

t def

ectiv

eF

lam

e se

nsor

foul

ed/d

efec

tive

Wai

t unt

il en

d of

del

ayed

shu

t-of

f

Wai

t unt

il te

mpe

ratu

re fa

lls b

elow

the

trig

gerin

g po

int

Rep

lace

tem

pera

ture

sen

sor

Che

ck li

ne

Top

up

cool

ing

wat

erB

leed

wat

er c

ircui

tR

epla

ce w

ater

pum

p

Ope

rate

saf

ety

ther

mal

cut

out s

witc

h

Ele

ctric

line

to m

eter

ing

pum

pin

terr

upte

dIn

suffi

cien

t coo

ling

wat

erW

ater

circ

uit n

ot p

rope

rly b

led

Wat

er p

ump

defe

ctiv

e

Rep

lace

flam

e se

nsor

Mea

sure

fuel

qua

ntity

Rep

lace

par

tial-l

oad

resi

stor

Re-

rout

e lin

eR

epla

ce c

ontr

ol u

nit

Cle

an/r

epla

ce fl

ame

sens

or

Fau

lt de

scrip

tion

Function and fault test for unit B 7 W 20 1673 05 00 00 – 12 Volt,D 7 W 25 1666 05 00 00 – 12 Volt and 25 1667 05 00 00 – 24 Volt

3

Mea

sure

fuel

qua

ntity

Fue

l lin

e be

com

es to

o ho

t – r

e-ro

ute

line

Cle

an/r

epla

ce fu

el s

enso

r

Insu

ffici

ent f

uel

Vap

our

lock

in th

e fu

el li

ne?

Fla

me

sens

or fo

uled

/def

ectiv

e

Cha

rge

batte

ryC

heck

reg

ulat

orU

nder

volta

geO

verv

olta

ge




4

01

23

45

67

89

1011

1213

Indi

catio

n

Sec

onds

Sig

nal

Cau

seR

emed

y

Fau

lt de

scrip

tion

Glo

w p

lug

defe

ctiv

e

Bur

ner

mot

or d

efec

tive

Cut

out d

ue to

unde

rvol

tage

Cut

out d

ue to

over

volta

ge

Non

- s

tart

Saf

ety

time

exce

eded

and

auto

mat

ic c

utou

t

Glo

w p

lug

fuse

def

ectiv

eG

low

plu

g de

fect

ive

Fla

me

sens

or fo

uled

/def

ectiv

e

Hea

ter

fuse

def

ectiv

eE

lect

ric m

otor

def

ectiv

e or

blo

wer

bloc

ked

Fla

me

sens

or fo

uled

/def

ectiv

e

Und

ervo

ltage

Cor

rosi

on o

n el

ectr

ical

conn

ectio

ns

Ove

rvol

tage

No

fuel

Met

erin

g pu

mp

defe

ctiv

eS

hort

-circ

uit a

t met

erin

g pu

mp

No

puls

es a

t met

erin

g pu

mp

Fue

l lin

e no

t fill

ed

Insu

ffici

ent f

uel

Glo

w p

lug

defe

ctiv

e

Aut

omat

ic c

utou

t afte

r 3

– 5

min

s.F

lam

e se

nsor

wro

ngly

pol

ed

Fla

me

sens

or fo

uled

Fla

me

sens

or in

terr

uptio

n

Insu

ffici

ent f

uel

Rep

lace

fuse

Rep

lace

glo

w p

lug

Cle

an/r

epla

ce fl

ame

sens

or

Rep

lace

fuse

Rep

lace

blo

wer

Cle

an/r

epla

ce fl

ame

sens

or

Cha

rge

batte

ry, c

heck

bat

tery

Cle

an e

lect

rical

con

nect

ions

Rep

lace

met

erin

g pu

mp

Che

ck p

lug

Rep

lace

con

trol

uni

tR

esta

rt, c

heck

fuel

line

Mea

sure

fuel

qua

ntity

Rep

lace

glo

w p

lug

Che

ck c

onne

ctio

n ag

ains

t wiri

ngdi

agra

mC

lean

flam

e se

nsor

Rep

lace

flam

e se

nsor

Mea

sure

fuel

qua

ntity

Che

ck r

egul

ator

Con

nect

hea

ter

to b

atte

ry




5

Indi

catio

nC

ause

Rem

edy

Fau

lts n

ot s

how

nby

the

indi

cato

r:

Sco

oty

com

bust

ion

Hea

ter

does

not

reg

ulat

e in

„Low

” se

tting

No

war

m a

ir in

inte

rior

Com

bust

ion

air

line/

exha

ust

line

clog

ged

Met

erin

g pu

mp

conv

eyin

g to

o m

uch

Com

bust

ion

air

blow

er s

peed

too

low

Dep

osits

in h

eat e

xcha

nger

Rem

ove

clog

Mea

sure

fuel

qua

ntity

Rep

lace

blo

wer

Rem

ove

and

clea

n he

atex

chan

ger

Tem

pera

ture

sen

sor

shor

t-ci

rcui

ted

(veh

icle

blo

wer

doe

s no

t sw

itch

onab

ove

appr

ox. 5

5°C

wat

er te

mpe

ratu

re)

Hea

ter

leve

r cl

osed

Veh

icle

blo

wer

not

sw

itche

d on

Veh

icle

blo

wer

rel

ay d

efec

tive

Veh

icle

blo

wer

fuse

def

ectiv

e

Rem

ove

tem

pera

ture

sen

sor

Ope

n he

ater

leve

r

Sw

itch

on v

ehic

le b

low

er

Rep

lace

rel

ay

Rep

lace

fuse



6

Fau

lt co

deF

ault

desc

riptio

n0

Indi

catio

n

87

65

43

21

000

No

faul

t

010

Ove

rvol

tage

sw

itch-

off

011

Und

ervo

ltage

sw

itch-

off

001

Pre

-hea

ting,

ove

rvol

tage

002

Pre

-hea

ting,

und

ervo

ltage

012

Ove

rhea

ting

013

Tem

pera

ture

at h

eat e

xcha

nger

to h

igh

020

Glo

w p

lug

defe

ct

022

Sho

rt c

ircui

t in

curr

ent r

egul

ator

cont

acts

023

Inte

rrup

tion

in c

urre

nt r

egul

ator

024

Sho

rt c

ircui

t in

curr

ent r

egul

ator

coi

l

Vol

tage

at c

ontr

ol u

nit (

betw

een

A12

and

B12

) gr

eate

rth

an 1

5 V

for

long

er th

an 2

0 se

c.

Vol

tage

at c

ontr

ol u

nit (

betw

een

A12

and

B12

) le

ssth

an 1

0.2

V fo

r lo

nger

than

20

sec.

Fla

me

sens

or h

as r

epor

ted

tem

pera

ture

> 5

60 °

C(c

orre

spon

ding

to 3

000

Ω).

Che

ck s

enso

r (c

onne

ctio

ns A

4an

d A

5 at

con

trol

uni

t).

Che

ck g

low

plu

g re

lay

(cur

rent

reg

ulat

or).

Che

ck c

onne

ctio

n to

glo

w p

lug,

che

ck c

onne

ctio

nto

con

trol

uni

t.

Che

ck g

low

plu

g. C

heck

con

nect

ions

to g

low

plu

g an

d to

glow

plu

g re

lay

(2.5

.5).

Che

ck c

onne

ctio

n to

con

trol

uni

t.

Che

ck c

oil c

onne

ctio

n to

glo

w p

lug

rela

y(c

onne

ctio

ns 8

5 an

d 86

).C

heck

con

nect

ion

to c

ontr

ol u

nit (

conn

ectio

n B

6).

Che

ck c

oil c

onne

ctio

n at

glo

w p

lug

rela

y(c

onne

ctio

ns 8

5 an

d 86

).C

heck

con

nect

ion

to c

ontr

ol u

nit (

conn

ectio

n B

6).

Rem

edy

Fau

lt si

gnal

/ fla

shin

g co

de

Ove

rhea

ting

switc

h ha

s tr

igge

red,

ven

t hea

ter

(lack

of w

ater

),op

en h

eatin

g va

lve,

che

ck w

ater

flow

and

sw

itch

Sec

onds

Vol

tage

at c

ontr

ol u

nit (

betw

een

A12

and

B12

) gr

eate

rth

an 1

4.5

VV

olta

ge a

t con

trol

uni

t (be

twee

n A

12 a

nd B

12)

less

than

11

V

Function and fault test for unit D 7 W 25 1807 05 00 00 – 12 Volt(Control unit 25 1732 50 00 04 0C)




7

Fau

lt co

deF

ault

desc

riptio

n0

Indi

catio

n

87

65

43

21

025

Sho

rt c

ircui

t at d

iagn

osis

out

put

Rem

edy

037

Wat

er p

ump

does

not

rot

ate

047

Sho

rt c

ircui

t in

met

erin

g pu

mp

051

Fla

me

sens

or d

efec

t

053

Fla

me

abor

t in

”larg

e” s

tage

059

as D

9 W

055

Fla

me

abor

t in

”sm

all”

stag

e

030

031

032

033

Ch

eck

wa

ter

pu

mp

(e

xte

rna

l tri

gg

eri

ng

).C

he

ck c

on

ne

ctio

ns

to c

on

tro

l un

it(c

on

ne

ctio

ns

A11

an

d A

13

).

Ch

eck

me

teri

ng

pu

mp

. C

he

ck c

on

ne

ctio

ns

toco

ntr

ol u

nit

(co

nn

ect

ion

s A

10

an

d B

10

).

See

D 9

W

See

D 9

W

See

D 9

W

See

D 9

W

No

fla

shin

g c

od

e

Fau

lt si

gnal

/ fla

shin

g co

deS

eco

nd

s

Com

bust

ion

air

fan

does

not

rot

ate

052

Fai

lure

to s

tart

/saf

ety

time

expi

red

Tem

pe

ratu

re a

t fla

me

se

nso

r d

oe

s n

ot

fall

be

low

80

°C

(co

rre

spo

nd

ing

to

13

00

Ω).

Ch

eck

fla

me

se

nso

r o

rco

mb

ust

ion

, p

oss

ibly

re

pla

ce.

(Se

tpo

ints

: 9

00

Ω t

o –

25

°C

, 11

00

Ω t

o +

25

°C

).

Ch

eck

dia

gn

osi

s le

ad

(co

nn

ect

ion

A1

at

con

tro

l un

it).

Ch

eck

co

nn

ect

ion

to

co

ntr

ol u

nit.

Ch

eck

co

mb

ust

ion

air

fa

n.

Ch

eck

mo

tor

spe

ed

re

lay

(2.5

.8).

Ch

eck

co

nn

ect

ion

to c

on

tro

l un

it (c

on

ne

ctio

ns

A11

an

d B

1).




8

Fau

lt co

deF

ault

desc

riptio

n0

Indi

catio

n

87

65

43

21

Rem

edy

060

Inte

rrup

tion

in te

mpe

ratu

re s

enso

r

061

Sho

rt c

ircui

t in

tem

pera

ture

sen

sor

090

Con

trol

uni

t def

ect (

inte

rnal

res

et)

092

RO

M fa

ult

093

RA

M fa

ult

094

EE

PR

OM

faul

t

095

Con

trol

uni

t def

ect (

gene

ral f

ault)

096

Con

trol

uni

t def

ect (

gene

ral f

ault)

097

Con

trol

uni

t def

ect o

r ca

ble

harn

ess

faul

t

For

faul

ts n

ot s

how

n he

re, p

leas

e se

e pa

ge 5

091

Ext

erna

l int

erfe

renc

e vo

ltage

064

Inte

rrup

tion

in fl

ame

sens

or

065

Sho

rt c

ircui

t in

tem

pera

ture

sen

sor

Rep

lace

con

trol

uni

t.

Che

ck a

nd w

here

nec

essa

ry r

epla

ce c

ontr

ol u

nit.

Che

ck c

able

har

ness

.

Mea

sure

d te

mpe

ratu

re li

es o

utsi

de m

easu

ring

rang

e.C

heck

sen

sor.

(Set

poin

ts: 6

50 Ω

at –

25 °

C, 1

000

Ω a

t +25

°C

).C

heck

con

nect

ions

to c

ontr

ol u

nit (

conn

ectio

ns A

5 an

d A

6).

Mea

sure

d te

mpe

ratu

re li

es o

utsi

de m

easu

ring

rang

e.C

heck

sen

sor.

(Set

poin

ts: 9

00 Ω

at –

25 °

C, 1

100

Ω a

t +25

°C

).C

heck

con

nect

ions

to c

ontr

ol u

nit (

conn

ectio

ns A

4 an

d A

5).

Che

ck v

olta

ge s

uppl

y.C

heck

con

nect

ion

to c

ontr

ol u

nit (

conn

ectio

ns A

12 a

nd B

12).

Sec

onds

Fau

lt si

gnal

/ fla

shin

g co

de



If the heater has ignited properly and is heating without trouble,the temperature sensor switches on the vehicle blower when thecooling water temperature is approx. 55 °C.

Various operating conditions can now result in the heating circuitdepending on the heat requirement.

Heat requirement 7000 W

If the heat requirement is 7000 W and more, the heater alwaysoperates in the „High” setting.The cooling water temperature rises to a approx. 90 °C.

Heat requirement 1750 W to 7000 W

After switch-on, the heater operates in the „High” setting.When a cooling water temperature of approx. 90 °C is reached,the heater switches to the „Low” setting.Since the heat requirement is greater than 1750 W the coolingwater temperature drops.When approx. 80 °C is reached the heater switches back to the„High” setting.

Heat requirement less than 1750 W

After switch-on, the heater operates in the „High” setting.

When a cooling water temperature of approx. 90 °C is reached,the heater switches to the „Low” setting.The temperature continues to rise due to the low heatrequirement.At approx. 94 °C the heater starts with delayed shut-off operationand cuts out after approx. 120 seconds.

The water pump and the vehicle blower remain in operationduring the delayed shut-off and the control interval. The pilotlight stays on.

Once the coolant has cooled down to approx. 80 °C, the heaterrestarts in the „High” setting.

Control in heating operation

9

CONTROL DIAGRAM

<1750 W

1750 – 7000 W

=7000 W

Heat requirement:°C

95

90

85

80

75

70

65

60

55

Time

Hig

h

Low

Low

High

Low

High Low

Low

High

Interval

Interval

High



Function sequence „Starting and control operation”

Master switch ON

Temperature < 55 °C

Temperature > 55 °C

Temperature 80 – 90 °C

Temperature 90 – 80 °C



Test 3 – 6 s

Preheat 20 – 60 s

Safety time 90 s

After-heat 20 – 30 s

Breakaway lock 30 s

Motor time-lag 4 s – 10 s(burner motor)

Flame sensor

Vehicle blower

Electric motor „High”(burner motor)

Water pump 2)

Electric motor „Low”(burner motor)

Glow plug

Fuel meteringpump „High”

Fuel meteringpump „Low”

Test

1)

Pre

heat

Saf

ety

time

Afte

r-he

at

Bre

akaw

ay lo

ck

„Hig

h” o

pera

tion

Inte

rval

„Low

” op

erat

ion

„Hig

h” o

pera

tion

Mas

ter

switc

h O

FF

Del

ayed

shu

t-of

f

10

Delayed shutoff 120 s

1) not for unit 25 1807 05 00 002) for unit 25 1807 05 00 00: no water pump during test



Wiring diagram for units B 7 W 20 1673 05 00 00 – 12 Volt and D 7 W 25 1666 05 00 00 – 12 Volt

Par

ts li

st1.

1B

urne

r m

otor

1.11

Ser

ies

resi

stor

for

part

ial l

oad

1.2

Glo

w p

lug

1.5

Saf

ety

ther

mal

cut

out s

witc

h1.

5.1

Saf

ety

ther

mal

cut

out f

use

1.12

Fla

me

sens

or1.

13T

empe

ratu

re s

enso

r

2.1

Con

trol

uni

t2.

2F

uel m

eter

ing

pum

p2.

5.7

Rel

ay fo

r sw

itchi

ng o

n ve

hicl

ebl

ower

2.7.

1F

lat f

use

15 A

– h

eate

r(8

A r

ound

fuse

)

a)br

eak

b)if

requ

ired

conn

ectio

n of

rel

ay c

oil f

or tr

igge

ring

wat

er s

olen

oid

valv

ec)

wat

er p

ump

exte

rnal

con

trol

(if

requ

ired)

d)br

oken

her

e w

ith th

e cu

rren

t reg

ulat

or c

onne

cted

f)te

st (

wor

ksho

p)g)

to te

rmin

al 1

5h)

only

for

heat

ers

with

sep

arat

e w

ater

pum

pi)

light

ing

to te

rmin

al 5

8

Mea

sure

vol

tage

:be

twee

n th

e co

ntro

l uni

t plu

gs,

A te

rmin

al 4

, and

C te

rmin

al 6

.C

able

col

ours

:rt

= r

ed, b

r =

bro

wn,

sw

= b

lack

, gn

= g

reen

,ge

= y

ello

w, v

i = v

iole

t, gr

= g

rey

2016

7300

9601

-3

11

3.1.

1U

nive

rsal

sw

itch

3.1.

2S

witc

h (h

eatin

g), c

ontin

uous

oper

atio

n3.

2.1

Tim

er (

anal

og)

3.2.

3D

igita

l tim

er, s

quar

e3.

2.4

Dig

ital t

imer

, rec

tang

ular

3.7

Cur

rent

reg

ulat

or5.

1B

atte

ry5.

1.2

Veh

icle

fuse

box

5.9.

1S

witc

h fo

r ve

hicl

e bl

ower

5.10

Veh

icle

blo

wer

2.7.

4F

lat f

use

20 A

– g

low

plu

g(1

6 A

rou

nd fu

se)

2.7.

5F

lat f

use

25 A

– v

ehic

le b

low

er(2

5 A

rou

nd fu

se o

r sa

me

as v

ehic

lem

anuf

actu

rer)

2.7.

10F

use

box

2.12

Wat

er p

ump



Par

ts li

st1.

1B

urne

r m

otor

1.1.

1S

erie

s re

sist

or fo

r pa

rtia

l loa

d1.

2G

low

plu

g1.

2.1

Ser

ies

resi

stor

for

glow

plu

g1.

5S

afet

y th

erm

al c

utou

t sw

itch

1.5.

1S

afet

y th

erm

al c

utou

t fus

e1.

12F

lam

e se

nsor

1.13

Tem

pera

ture

sen

sor

2.1

Con

trol

uni

t2.

2F

uel m

eter

ing

pum

p2.

5.7

Rel

ay fo

r sw

itchi

ng o

n ve

hicl

e bl

ower

2.7.

1F

lat f

use

15 A

– h

eate

r(8

A r

ound

fuse

)

a)br

eak

b)if

requ

ired

conn

ectio

n of

rel

ay c

oil f

ortr

igge

ring

wat

er s

olen

oid

valv

ec)

wat

er p

ump

exte

rnal

con

trol

(if

requ

ired)

f)te

st (

wor

ksho

p)g)

to te

rmin

al 1

5h)

only

for

heat

ers

with

sep

arat

e w

ater

pum

pi)

light

ing

to te

rmin

al 5

8

Mea

sure

vol

tage

:be

twee

n th

e co

ntro

l uni

t plu

gs,

A te

rmin

al 4

, and

C te

rmin

al 6

Cab

le c

olou

rs:

rt =

red

, br

= b

row

n, s

w =

bla

ck, g

n =

gre

en,

ge =

yel

low

, vi =

vio

let,

gr =

gre

y

2516

6700

9601

-1

D 7 W 25 1667 05 00 00 – 24 Volt

12

3.1.

1U

nive

rsal

sw

itch

3.1.

2S

witc

h (h

eatin

g), c

ontin

uous

oper

atio

n3.

2.1

Tim

er (

anal

og)

3.2.

3D

igita

l tim

er, s

quar

e3.

2.4

Dig

ital t

imer

, rec

tang

ular

5.1

Bat

tery

5.1.

2V

ehic

le fu

se b

ox5.

9.1

Veh

icle

blo

wer

sw

itch

5.10

Veh

icle

blo

wer

2.7.

4F

lat f

use

20 A

– g

low

plu

g(1

6 A

rou

nd fu

se)

2.7.

5F

lat f

use

25 A

– v

ehic

le b

low

er(2

5 A

rou

nd fu

se o

r sa

me

as v

ehic

lem

anuf

actu

rer)

2.12

wat

er p

ump



Wiring diagram for unit D 7 W 25 1807 05 00 00 – 12 Volt (Parts list see page 14)

25 1807 00 96 01

13



Wiring diagram for unit D 7 W 25 1807 05 00 00 – 12 Volt

25 1807 00 96 01

14

Parts list

1.1 Burner motor1.1.1 Resistance for burner motor (partial load)1.2 Glow plug1.5 Overheating switch1.12 Flame controller1.13 Temperature sensor

2.1 Control unit2.2 Fuel metering pump2.5.4 Switch-on relay2.5.5 Glow plug timing2.5.7 Relay vehicle fan2.5.8 Relay motor speed switch-over2.7 Main fuse (25 A)2.7.1 Fuse activation (5 A)2.7.5 Fuse vehicle fan (25 A)2.12 Water pump2.15.9 Sensor, outer temperature

3.1.2 Heating switch (continuous operation)3.2.5 Timer, 7 days3.2.6 Timer, mini3.4.5 „On“ control lamp

5.1 Battery5.1.2 Fuse strip in vehicle5.9.1 Vehicle fan switch5.10 Vehicle fan

a) Connection for operator deviceb) External triggering for water pumpc) Temperature loweringd) Switch-over solenoide) Illumination terminal 58f) to terminal 15g) split leadh) remove S3 and fit S4

Connector and jack housings are shownfrom the lead incoming side.



Repair instructionsAvailable spare parts: see spare parts list

Repair procedures

1. Removing the glow plug2. Removing the plug filter3. Removing the series resistor4. Removing the cover5. Removing the 12-pin plug

10. Removing the water pump11. Removing the combustion air blower12. Removing the burner13. Removing the heat exchanger14. Removing the cover and bracket15. Bleeding the coolant system

6. Removing the temperature sensor7. Removing the flame sensor8. Removing the safety thermal cutout fuse/switch9. Removing the partial-load resistor

➀ Plug filter

➁ Reduction piece

➂ Sealing ring

Sketch 2Sketch 1

1. Removing the glow plug

Remove glow plug cap.Unscrew hexagonal nut and take off plug cable.Unscrew glow plug.Remove any charring on the glow plug coil, or replace glow plug.

Important!Additional maintenance work when glow plug fails.Clean flame sensor.Clean combustion air intake in glow plug fitting with a brush orwith another suitable tool. To do so, unscrew the glow plug andpull out the plug filter.If the heater is fitted with a plug adapter, unscrew the adapter.Check the plug filter and replace if severely clogged.

For D 7 W onlyMeasure the glowing time of the glow plug after the flame.Install and connect up the glow plug.Connect a test lamp to the glow plug and keep a stop clockready.Switch on heater and measure glowing time of the glow plugafter the flame.The glowing time may be 30 – 60 seconds.If the glowing time exceeds 60 seconds, measure fuel quantity,check fuel pipes, if necessary replace flame sensor.

2. Removing the plug filter

Unscrew glow plug.If the heater is fitted with a plug adapter, unscrew the adapter.Remove the plug filter from the glow plug fitting.

Please note:During installation, please insert the plug filter in the plug fittingas shown in diagram 1 and 2.

15

Fig. 2

Fig. 1



Fig. 5

3. Removing the series resistor

Remove the cap from the series resistor.Loosen the hex. nut.Detach the cable.Unscrew the series resistor.

4. Removing the cover

Unclip the cover from the holder using a screwdriver.

Note when installing:The cover cap must be fitted splash-water tight, so ensurethat all grommets are properly positioned.

5. Removing the 12-pin plug

Remove the cover.Unclip the plug from the holder using a screwdriver.Dismantle the plug.

16

Sketch 3

* There is no connector pin 4 in unit 25 1807 05 00 00 – 12 volt.

Safety thermal cutout fuse 0,52 ws Flame sensor 0,52 gr Flame sensor 0,52 br Partial-load resistor 12 rt Combustion air blower 12 brWater pump 12 sw

Water pump 12 br Combustion air blower 12 vi Partial-load resistor 12 rt Temperature sensor 0,52 br Temperature sensor 0,52 gr Safety thermal cutout fuse 0,52 ws

2 4* 6 8 10 121 3 5 7 9 11

Fig. 3

Fig. 4

Note:After removing the 12-pin connector, connect cable harnessback to connector, then remove connector lid (if cable harnessis not connected again, all the connector pins will fall out).



Fig. 7a

6. Removing the temperature sensor

Before removing the sensor, reduce the excess pressure in thecooling system by opening the radiator filler cap. To prevent thecoolant from flowing out pinch the water supply and returnhoses shut.Remove the cover.Remove the 12-pin plug (note instructions on page 16).Take the plug pins 8/10 out of the plug housing(see sketch 3 page 16).Unscrew the temperature sensor.

After installation, bleed the water circuit.See repair procedure 15.

7. Remove flame sensorfor units B 7 W 20 1673 05 00 00 – 12 V olt,D 7 W 25 1666 05 00 00 – 12 Volt and 25 1667 05 00 00 – 24 Volt

Remove cover.Take out 12-pin connector (note instructions on page 16).Remove connector pins 7/9 from connector housing(see sketch 3 page 16).Unclip spring retainer.Remove flame sensor from holder.

7a. Remove flame sensorfor unit D 7 W 25 1807 05 00 00 – 12 Volt

Remove cover.Take out 12-pin connector (note instructions on page 16).Remove connector pins 7/9 from connector housing(see sketch 3 page 16).Unscrew flame sensor from exhaust fitting using wrenchsize SW 9.

17

Fig. 6

Fig. 7



Fig. 8

8. Remove overheating switch or overheating fuse for unitsB 7 W 20 1673 05 00 00 – 12 Volt,D 7 W 25 1666 05 00 00 – 12 Volt and 25 1667 05 00 00 – 24 Volt

First the overpressure in the cooling system must be decreasedby opening the lid of the cooler cover.To prevent the coolant from leaking, pinch off the water inlet andwater outlet hoses. Remove the cover.Remove the 12-pin connector (note instructions page 16).Take connector pins 11/12 out of the connector housing(see sketch 3 page 16).Unscrew the overheating switch or overheating fuse.

Note when installing:The thread of the overheating switch or overheating fuse shouldbe greased with Molykote paste and the O-ring with Vaseline orother suitable lubricants.Screw in the overheating switch or overheating fuse by handonly until you can feel the resistance indicating that it is incontact with the heat exchanger.

Vent the water circuit after installation (see repair stage 15).

8a. Remove overheating switch for unitD 7 W 25 1807 05 00 00 – 12 Volt

First the overpressure in the cooling system must be decreasedby opening the lid of the cooler cover.To prevent the coolant from leaking, pinch off the water inlet andwater outlet hoses. Remove the cover.Remove the 12-pin connector (note instructions page 16).Take connector pins 11/12 out of the connector housing(see sketch 3 page 16).Unscrew the cross-recessed screws.Remove the (spring-loaded) overheating switch.

Note when installing:On removing the overheating screw, the O-ring and seal shouldbe replaced. Grease the O-ring with Vaseline or another suitablelubricant.

Vent the water circuit after installation (see repair stage 15).

Fig. 9

9. Removing the partial-load resistor

Remove the cover.Remove the 12-pin plug (note instructions page 16).Take the plug pins 5/6 out of the plug housing(see sketch 3 page 16).Remove the retaining clips from the partial-load resistor.Remove the partial-load resistor.

18

Fig. 8a



Fig. 10

10. Removing the water pump

Before removing the pump, reduce the excess pressure in thecooling system by opening the radiator filler cap.To prevent the coolant from flowing out pinch the water supplyand return hoses shut.Remove the cover.Remove the 12-pin plug (note instructions page 16).Take the plug pins 1/2 out of the plug housing(see sketch 3 page 16).Undo the fastening clip of the water pump.Remove the water pump.

Note when installing:A new O-ring must be fitted when the water pump is removed.Grease the O-ring with Vaseline or other suitable lubricants.

After installation, bleed the water circuit.See repair procedure 15.

11. Removing the combustion air blower

Remove the cover.Remove the 12-pin plug (note instructions page 16).Take the plug pins 3/4 out of the plug housing(see sketch 3 page 16).Loosen the fastening screw and remove the combustionair blower.

Note when installing:Grease the O-ring on the combustion air blower connectionwith Vaseline or other suitable lubricants.

Before fitting the combustion air blower to the heater, turnthe fastening screw into the blower housing to cut the tread.

Fig. 11

12. Removing the burner

Before removing the burner, reduce the excess pressure inthe cooling system by opening the radiator filler cap.To prevent the coolant from flowing out pinch the watersupply and return hoses shut.Remove the heater.Remove the combustion air blower.Remove the plug cable and – in the case of 24 V heaters –also the cable from the series resistor.Remove the flame sensor.Undo the clamping clip and remove the burner.

Note when installing:Check the O-ring for correct seating.

After installation, bleed the water circuit (see repairprocedure 15).

Check for tightness in a trial run.

19

Fig. 12



13. Removing the heat exchanger

Before removing the heat exchanger, reduce the excesspressure in the cooling system by opening the radiator filler cap.To prevent the coolant from blowing out pinch the water supplyand return hoses shut.Remove the heater.Remove the burner.Lift the safety thermal cutout fuse or switch off the heatexchanger by one turn.Remove the temperature sensor.Lever the heat exchanger out of the water jacket using screw-drivers. Remove the heater exchanger from the water jacket.(Fig. 13a).

Note when installing:Fit a new O-ring when the heat exchanger is removed.Grease the O-ring with Vaseline or other suitable agents.

14. Removing the cover and bracket

Remove the cover.Remove the 12-pin plug.Detach the 2-pin plug.Remove the partial-load resistor.Remove all grommets.Take the bracket off the jacket.

Note when installing:The cover cap must be fitted so that it is splash-water tight, soensure that all grommets are properly positioned.

20

Fig.13a

Fig. 13

Fig. 14



15. Bleeding the cooling water system

Se the heater lever fully in the „Warm” setting.Top up the cooling water.Start the vehicle engine and run it until the radiator thermostathas opened.

For units B 7 W 20 1673 05 00 00 – 12 Volt,D 7 W 25 1666 05 00 00 – 12 Volt and 25 1667 05 00 00 – 24 VoltTo vent the cooling water circuit (heater), trigger the water pumpat the control unit with +, 6-pin connector, terminal A6(see sketch 4).

For unit D 7 W 25 1807 05 00 00 – 12 VoltTo vent the cooling water circuit (heater), trigger the water pumpat the control unit with +, 13-pin connector, terminal B4(see sketch 5).

If necessary top up cooling water.Please refer also to the vehicle manufacturer’s instructions onbleeding the water circuit.

Check for tightness in a trial run.

Measuring the fuel quantity

Important: only measure the fuel quantity when the battery issufficiently charged. At least 11/22 V and at most 13/26 Vshould be applied at the control unit during measurement.

1. Preparation

Pull out the plug terminal underneath the cap on the heater andconnect a test lamp.Detach the fuel line from the heater and introduce it into ameasuring glass (size 25 cm3).

For units B 7 W 20 1673 05 00 00 – 12 Volt,D 7 W 25 1666 05 00 00 – 12 Volt and 25 1667 05 00 00 – 24 VoltConnect voltmeter to the 8-pin connector terminal C6 (+) and tothe 6-pole connector terminal A4 (–) of the control unit.

For unit D 7 W 25 1807 05 00 00 – 12 VoltConnect voltmeter to the 13-pin connector terminal A13 (+) andterminal A12 (–) of the control unit.

Switch on the heater. When fuel is being pumped evenly(approx. 25 – 55 seconds after switch-on), the fuel line is filledand bled. Switch off the heater and empty the measuring glass.

2. Measurement

Switch on the heater.Fuel starts being pumped some 25 – 55 seconds after switch-on.Hold the measuring glass at the level of the plug duringmeasurement. Read off the voltage at the voltmeter.Fuel feed is cut off automatically after 90 sec.Switch off the heater.Read off the fuel quantity in the measuring glass.

3. Evaluation

Transpose the readings into the appropriate diagram onpage 22.The fuel consumption is OK if the intersection of the tworeadings is within the limit curves.If the intersection is outside the limit curves, a new fuelmetering pump is required.

Sketch 6

21

1 2 3 4 5 6 7 8 1 2 1 2 3 4 5 6S T

1 2 3 45 6 7 8

1 2 34 5 6

Test

S

ABC

1 2 3 4 5 6 7 8 9 10A B

1 2 3 4 5 6 7 8 9 10

6 7 8 9 10

1 2 3 4 5 11 12 13678910

12345

111213

Sketch 5

Sketch 4

6 4

46

1213

1213

C B A

A B

Unit:D 7 W 25 1807 05 00 00 – 12 Volt

Unit:B 7 W 20 1673 05 00 00 – 12 VoltD 7 W 25 1666 05 00 00 – 12 VoltD 7 W 25 1667 05 00 00 – 24 Volt

Connection of voltmeterto control unit

➀ ➁

➁➀

➁

Positive lineto voltmeter

➀

Apply (+) here

Apply (+) here

Voltmeter

Control unit

Connect test lamp

Negative lineto voltmeter



Fuel diagrams

22

B 7 W D 7 W

D 7 WB 7 W

ml/60 s22

20

18

16

14

12

101020

1224

14 Volt28

ml/60 s22

20

18

16

14

12

101020

1224

14 Volt28

ml/90 s

31

29

27

25

23

21

191020

1224

14 Volt28

33

ml/90 s

29

27

25

23

21

19

171020

1224

14 Volt28

31



Documents

Water heater B 7 W/D 7 W · 2016-05-06 · Check combustion air fan. Check motor speed relay (2.5.8). Check connection to control unit (connections A11 and B1). Visit for more technical