Dometic RM182B User Manual

B)TDometic

Diagnostic Service Manuals

United States

SERVICE OFFICE

DOMETIC SALES CORP
509 South Poplar

LaGrange,

IN 46761

SERVICE

Edition

August 1982

DSC

#651

2

SERVICE MANUAL

RM182

When

ordering
MODEL.
For

electric

VOLTAGE -WATTAGE

spare parts always state:

QUANTITY * PART NUMBER * DESCRIPTION

details also:

REFRIGERATOR

B

TABLE OF CONTENTS

A.

Installation Instructions

B.

Instructions For Use

RM

182B

Page 2

Page 3
General Instructions
Sealed Combustion Unit
Ventilator (improved cooling performance)
Fuse

-

12 Volt Circuit

Steps To Take When The Refrigerator Has Not

Been Used For A Long Period
Pilot Outage
Periodic Maintenance

Removal And Installation Of Refrigerator

c.

Component Replacement

D.

Replacing The Electric Heating Element
Replacing Voltage Selection Switch
Replacing Gas Shut-Off Valve (Gas-Cock)

Replacing

Thermostat

And

Flame Failure Safety

Device (Safety Valve)

Replacing Thermo-current Adapter

Page 4
Page 4
Page 4
Page 4

Page 4
Page 4
Page 4

Page

5
Page 6
Page 6
Page 6
Page 6

Page

Page

6

7

&

7

Replacing Thermocouple
Replacing Spark Ignitor With Cable
Replacing Burner Jet

Cooling

Removing The Air

Wiring Diagram

E.

Troubleshooting The Refrigerator- L.P. Gas

F.

Troubleshooting The Refrigerator - Electric

G.

Figures 1 through

H.

Unit Replacement

The Piston

(Joint

15

RM 182 B

Pump

And

Ring)

Replacing

Page
Page
Page
Page

7

7

8

8

Page 9

Page 9

Page l0

Page 11
Page 12

-

-l-

A.

INSTALLAT

INSTRUCT IONS

ION

The design of this refrigerator has been certified and approved by the American

Gas Association and the Canadian

This certification is dependent,

GAS

Association for

Recreational Vehicles.

however upon proper installation’-and the use of

the venting components as shown in these instructions.

Installation

The installation of the refrigerator must

sence of local codes

the following American National Standards and Canadian Stan-

dards are applicable

In the USA:

ANSI z
ANSI c

223.1.­1

1978 National Fuel Gas Code
1978 National Electric Code

In Canada:

CSA Std. Z 240.4.

-

*Gas Equipped Recreational

Vehicles and Mobile Housing

*Note:
and Z 24o.4.2.
CSA Std. Z

Will be replaced by CSA Stds. Z

when available.

24o.6.1.

-

Electrical Requirement for

Mobile Housing

CSA

Std. Z

24o.6.2.

-

Electrical Requirement for

Recreat

comply with local codes or in the ab-

24o.4.1

ional

Vehicles

-2-

B. INSTRUCTIONS FOR USE

RM182B

The Controls

Control Panel : Fig. 1 Page 1

1.
“A”

-

"B"

-

"C"

_

:

Controls are located at the top of the refrigerator.

___

Air Pump and Piezo Lighter

Safety Valve

Thermostat for Gas and 120

the unit runs

continously)

Volt Operation (12 volt has no thermostat,

Voltage Selector Switch

Gas Shut-Off Valve
Flame Pilot Sight Peep

2.

Gas Operation

_________ ____________ ____ ___________

1.

Place Voltage Switch
Valve

2.

3.

4.

Turn thermostat "C" (Fig. 1) to

Depress button
Release button "B" and pump knob "A" (Fig. 1) 20 times DO

-

Lighting the Burner

"D"

"E"

(Fig.1) to position

"B"

(Fig. 1) for 20 seconds to let gas flow to burner

(Fig. 1) on position

until click is heard, stop short of this position.

5.

Once again, press button

knob

“A” (Fig. 1) several times until

"B"

is Piezo Lighter).

6.

7.

When burner is lit, hold button

Flame may be observed through pilot sight peep "F" (Fig. 1) and ice
tray should show signs of cold after two hours.

A

,

then place Gas

I

maximum

NOT

pump

(Fig. 1) and hold, simultaneously pump

noticable

"B'

(Fig. 1) for at least lo seconds.

click is heard (this

3.

Electrical Operation

1.

2.

_

Place Gas Valve "E" (Fig. 1) to position 0
Place Voltage Selector Switch

NOTE:
cause of an inserted relay, the 12 Volt operation is only possible

if the car ignition is switched on.

4.

Temperature Control

_______

_______________

With the thermostat knob "C" (Fig. 1) set at the middle position, the
cabinet will automatically maintain a suitable temperature for ordinary

food storage.
hot weather, or when more cooling is required, the knob

must be turned to a higher position.

If less cooling is required, the knob should be turned to a lower

sition.

If knob

circuit is switched off. During gas operation the same position corres-

ponds to

_______

"D"

(Fig.

1) to the appropriate voltage.

The 12 volt circuit is not thermostatically controlled, Be-

Usually, no further adjustment will be necessary, but in

"C"

(Fig. 1)

"C"

(Fig. 1) is turned completely to the left, the

Minimum

Cooling.

120

Volt

po-

-3-

General Instructions

Sealed Combustion Unit

The sealed canbustion unit is made up of the burner, a fresh air intake and
exhaust pipes, and a vent/air-intake assembly in the wall.

The burner unit is completely sealed off’
of the two special inlet and outlet pipes.

from the interior of the van by means

In the vent /air-intake assembly,

fresh air is drawn in one pipe and combusted gases are safely vented to the

outside through the other pipe.

Ventilator (Cooling Fan)

In order to improve the cooling performance under the difficult built-in situ-

ation and high ambient temperatures,

matically when the temperature around the

140~

gerator) reaches

NOTE:

F and switched off at 124 F.

a o,6 W ventilator is switched on auto-

condenser

fins (behind the refri-

The ventilator is connected to the 12 V-circuit in such a manner that it is

also operational during the 120 V and gas operations.

Fuse

For 12 V use the refrigerator is protected by a fuse installed in the gene­ral electrical circuit of the vehicle. If the fuse bums out, trace the cause
and correct it before fitting a new lo amp. fuse.

Steps To Take When The Refrigerator Has Not Been Used For A Long Period

If there has been a heavy rain,or the vehicle has been through a car wash,

be_

water may have collected in the burner housing. This must

the gas is lit.

For this, the sealing plug underneath the front of the refri-

removed before

gerator on the left is unscrewed from the drainage tube and the water is
allowed to escape.

The sealing plug must then be carefully refitted since a

good seal is essential for the proper function of the combustion system._ Check

that the windscreen of the outside wall of the van is clean and remove any

dirt that is present.

Pilot Outage

It has been determined that this problem can be causedbya poor seal between

"E"

the slide for ventilation housing

(Fig.2) and the side wall of the ve-

hicle.
When properly sealed,

this plate acts as a baffle to protect the exhaust out­let tube from direct air flow. If this seal is not complete, air will be
allowed to flow between the plate and the side wall of the vehicle directly
into the exhaust outlet tube.

"D"

This problem can be caused by failure to tighten the mount

"F"

properly, a bad gasket

(Fig.2) or a warped locating plate

(Fig. 2) screws

"E"

(Fig. 2).

Periodic Maintenance

Once or twice a year, depending on use,

it is necessary to clean and adjust

the burner assembly.

The burner ist fitted with a # 24 jet, which is suitable for use on Propane

or Butane gas at a supply pressure of 11 inches water column pressure. The
orifice in the jet is very small and must never be cleaned by means of a pin
or a similar instrument for this will damage the orifice. Should, for

reason,

the jet require cleaning,

it should be washed in alcohol and blown

some

dry with air.
The entire gas installation should be checked for leaks. Test all pipe connec-

tions with soapy water, not with an open flame.

-4-

C.

REMOVAL

AND INSTALLATION OF REFRIGERATOR

Remova

1.

1

Disconnect electrical supply. And make sure the

gas supply is shut off at

its source.

2.

Remove the vent /air-intake assembly on the van

a. Unscrew three self-tapping screws

(A,Fig.2)

then remove windscreen and separating plate

b. Unscrew four screws

(D,Fig.2)

of the fixing

fixing plate and gasket (F, Fig. 2) from the

wall outside .
of the windscreen

(B,Fig.2)

(C, Fig. 2).

plate (E,Fig. 2) and remove

caravan wall (G, Fig. 2) to

the vent casing (H,Fig. 2).

3.

Open and remove all three doors of the kitchen cabinet (Fig.3). Pull out dra­wer. Dismantle and remove shelves. Then lift door from hinge posts (Fig.3).

4.

Remove three protective caps (A, Fig.4) from the refrigerator frame

(B,Fig.4)
and unscrew the three screws that are behind the caps. Then on each side
through the doors,unscrew two

phillips

screws (C, Fig.4) from the walls of

the refrigerator.

5.
t en pull out the left groove according to arrow

F

6.

Remove 120 V connection plug (A, Fig.6) from the socket, pull out 12 V plug

pull refrigerator frame forward in the lower right (Fig.

(B,Fig.S)

toward the right.

5,arrow

connection (B, Fig.6).
Unscrew threaded union of the gas-connection line

(C,Fig.6)

of the refrige-

rator.

A)

7.

Unscrew ventilation grill (A. Fig. 7) by removing two screws (B, Fig. 7) and

then remove refrigerator by pulling forward.

Installation

The installation is carried out in the reverse sequence to that described for

the removal of the refrigerator.

IMPORTANT:

After installation, check gas system for leaks, with soapy water.

NEVER USE A

MATCH

-5-

D.

COMPONENT

NOTE:

REPLACEMENT RM182B

For the removal of gas and electrical components and of the refrigerator
cooling unit, the refrigerator must be removed from the kitchen cabinet

(see chapter C)

.

1. Replacing the electric heater

_____

1. Squeeze the heater insulation in direction of arrow (A,Fig. 8) until it
clicks open. Pull open the insulation in direction of arrow ( B,Fig. 8)
and remove it .

2. Unscrew fixing screw (C, Fig. 8) of the heater and remove the heater from

its pocket by pulling straight up.

3. Unscrew the two screws of the cover (F,Fig. 9) exposing the terminal
block.

4. Unscrew the heater cable at the terminal block and remove heater with
cable.

5. To replace heater,

NOTE

:

reverse the procedure.

The heater has a groove (D, Fig. 8) at the bottom, into which the fi-

xing screw fits.Place the new heater inside the heater tube so that
the groove is in the correct position for the fixing screw. The bottom
of the heater should be level with the bottom of the heater tube.

2. Replacing the voltage selection switch

_____

(D,Fig.9)

1. Remove plug-connections of the voltage selection switch.

2. Press in the four fixing legs on the switch and at the same time press out
the switch from the control panel.

3. To replace switch,reverse the procedure.

3. Replacing the gas-cock G Fig. 9)

_____

1. Unscrew union nut (H, Fig. 9) and union nut ( I, Fig. 9

2. Unscrew support bracket ( J, Fig 9) for gas-cock ( 2 screws

----- ___
)

) .

3. To replace gas-cock, reverse the procedure.

4. Replacing the thermostat and flame failure safety device

_____

(

Safety

______

Valve)

1. Remove ice-tray support (A, Fig. lo) from evaporator by withdrawing in
a forward direction.

CAUTION: Only take hold of it at the left side (indicated by the arrow). Now

pull the capillary tube of the thermostat off.

2. Bend straight the capillary tube from the rear of the cabinet.

3. Unscrew union nut (A, fig. 11) from gas-cock (B, fig. 11). (Use a second
fork-spanner to hold counterpart the gas-cock).

-6-

4.

Pull off thermostat knob (C,

(E, Fig. 11).

Fig.11)

and

knob

(D,

Fig.11)

of safety device

5.

Unscrew union nut (F,

Fig.11)

of gas-pipe (G,

Fig.11)

from flame failure

safety device (E, Fig. 11).

6.

Remove three cable plug-connections from thermostat (H,

7.

Unscrew thermo-coupling (I,

8.

Unscrew thermostat (H,

9.

Unscrew two clips (L,
Remove gas-equipment from cabinet and dismantle.

10.

11.

Dismantling of thermostat (H,

(E,

Fig.11)

(N,

Fig.11)

12.

Dismantling of the flame failure safety device (E,

with thermo-current adapter (J,
from thermostat.

Fig.11)

failure safety device from thermostat (H,

current adapter (J,
For reassembly, proceed in the reverse sequence of dismantling.

13.

CAUTION:

Coat threaded unions at the connection/thermostat and thermostat/flame

Fig.11)

Fig.11)

Fig.11)

from thermo-current adapter (J,

from support bracket (K,

from capillary tube (M,

:

Fig.11)

Unscrew flame failure safety device

Fig.11)

and the connection

Fig.11)

Fig.11).

Then unscrew

from the flame failure safety device.

Fig.11).

Fig.11)

Fig.11).

:

Unscrew flame

failure safety device with Loctite 572 to ensure good sealing.
Be careful not to get any Loctite inside any parts.

5.

Replacing

_____ _____ ____

1.

Unscrew thermo-coupling (I,

2.

Unscrew thermo-current adapter from flame failure safety device (E,

the thexmo-current adapter

Fig.11)

from thermo-current adapter.

(J,Fig.

11).

____

and replace by new unit.

Fig.11).

( 2 screws

thermo-

Fig.11)

).

(I,

Fig.

6. Replacing the thermocouple

_____ _____ ___

1.

Unscrew thermo-coupling from thermo-current adapter (J, Fig. 11).

2.

Unscrew clip (0,

Fig.11)

for gas-pipe (G,

3. Unscrew the three screws of the mounting plate (A,
part of gas-burner.

thermocouple (I,

4.

Unscrew lock-nut (D,

5.

Bend new thermocoupling (I, Fig.

Take off spark ignitor (B,

Fig.12)

and gasket (C,

Fig.12)

of the thermocouple

11)

11+12)

Fig.11)

and thermocouple.

Fig.12)

Fig.12),

mounting plate with

Fig.12).

to shape of old one. For reassemhly,

proceed in the reverse sequence of dismantling.

IMPORTANT:

The gasket (C,

Fig.12)

between the lower part of the burner and the

mounting plate must be replaced by a new one and carefully positioned

to ensure that the burner is properly sealed.

7. Replacement of spark

1.

Remove ignition cable (P,

2.

Unscrew the one screw (A3,

ignitor

with cable
Fig.11)

Fig.12)

ignitor and replace it by a new one.

from piezo

(B,Fig. 12)

ignitor

(Q,

from the spark ignitor, withdraw spark

Reassemble in the reverse order.

from the bottom

Fig.11).

-7-

8.

Replacing the burner-jet ( E Fig.

___ ____

12)

Unscrew union nut

1.

and a second one (14
Unscrew burner jet from the bottom part of gas-burner.

2.
Screw in the new burner jet, refit gas pipe.

3.

IMPORTANT:

The gasket (G,

(F,

Fig. 12) of gas pipe by using a lo mm fork-spanner

mm)

to hold counterpart the jet.

Fig.12)

between the lower part of the burner and
the burner-jet must be replaced by a new one and carefully posi­tioned to ensure that the burner is properly sealed.

9. Cooling unit replacement.

_________ ________

1.

Unscrew thermo-coupling (I,

2.

Unscrew clip (0,
Remove the three connections (A, Fig.

3.

Fig.11)

Fig.11)

from thermo-current adapter

for gas-pipe (G,

13/R,

Fig.11)

Fig.ll),

(J,Fig.ll).

and thermocouple.

unscrew support

bracket (B, Fig. 13) of the ventilator.

4.

Unscrew thermostat (S, Fig. 11) from condenser fins and remove plug-connec­tion of grounding cable (T, Fig. 11) above the condenser fins.

5.

Squeeze the heater insulation in direction of arrow (A, Fig.8) until it
clicks open. Pull open the insulation in direction of arrow (B, Fig. 8)
and remove it.

6. Unscrew fixing screw (C, Fig.8) of the heater and remove the heater from
its pocket by pulling straight up.

7.

Unscrew union nut (A, Fig. 14) of flexible exhaust pipe (B, Fig. 14)using
a pipe wrench,remove flexible pipe and gasket from gas heating-pipe

(C,Fig.l4).

8. Unscrew union nut (U,

Unscrew six screws (A,

9.

screws from support bracket (B,

lo. Take off bottom part of burner with thermocouple, gas pipe and spark

tor with cable from upper part of burner (D,

Fig.11)

Fig.15)

from air feed-pipe.

from the bottom part of gas burner and two

Fig.15)

of the drainage tube (C,

Fig. 15).

igni-

Fig.15)

by withdrawing to the

right side .

11. Unscrew upper part of gas burner (D,

fran the gas heating pipe (F,

Fig.15)

12. Unscrew locking plate from pilot sight peep (H,

Fig.15)

with air inlet pipe (E,

(2 screws G, Fig.

Fig.15).

Fig.15)

15).

13. Unscrew eight screws (I,Fig. 15) from the cooling unit attachment panel ‘and

take cooling unit out of the cabinet.

14. For the installation of the cooling unit, proceed in the reverse sequence.

CAUTION: The location of the thermostat capillary tube should be noted at

IMPORTANT

this time for relocation later on. The tubes

correct position otherwise, improper

:

The

gasket (H,

Fig.12)

between the lower and upper part of the

performance

must

be placed in the
will result..

burner must be replaced by a new one and carefully positioned

to ensure that the burner is properly sealed.

Also the gasket (I,

Fig.12)

between the upper part of the bur-

ner and the gas heating pipe should be replaced too.

-8-

lo. Removing the air

___________ __ _____ _____

1.

Unscrew knob (A, Fig.9) of air pump (K, Fig.9) from the shaft (L, Fig.9).

2.

Unscrew air pump ( 4 screws / M, Fig. 9).
Unscrew cover of air-pump ( 2 screws / N, Fig. 9).

3.

Withdraw shaft, force out retaining disc from the groove, pull off large

4.

pump

and replacing the piston.

disc and change joint ring.

Reassemble in the reverse order.

5.

CAUTION:

After all repairs to the gas equipment,the entire gas system must be

checked for leaks with soapy solution.

NEVER

E.

WIRING

USE A

DIAGRAM

MATCH

THERMOSTAT

RMINAL

TE

BLOCK

HEATER

1

HEATER

1

GREY

5 0

W
a

t$$i

P

MAINS CABLE

120V

y

w

5

5

s

+

z
iii

12V

SUPPLY CABLE

-9-

4 g

F. TROUBLESHOOTING THE REFRIGERATOR - L.P. GAS

SYMPTOM

CAUSE

NOTE: It will be noted in this guide that several causes can

for one effect.The real cause or causes should be
the process of elimination, investigating each possible cause, star­ting at the top of the guide and proceeding to the bottom.

Gas leaks
Inadequate ventilation
refrigerator not level
Jet orifice clogged
The thermocouple tip not in position
No contact between thermocouple and safety valve

-

Faulty safety valve magnet

-

Improper flame

-

By-pass flame too large

-

Vent air-intake assembly clogged

-

Unstable burner flame
Improper food storage

-

Thermostat incorrectly used

-

Improper storage of liquid and moist foods

-

Leaky cabinet seals

-

Ambient temperature too high
Flame contacts flue tube

-

Insufficient air to burner

-

Infrequent cleaning of food compartment

-

Refrigerator shut off with closed door

-

Unwrapped odorous food
Incomplete contact of the thermostat capillary tube

-

Thermostat charge lost

-

Refrigerator unit failure
Room temperature too low
Piezo

ignitor faulty

Piezo ignitor cable faulty

-

Water in the burner housing
Vent/air-intake assembly is not mounted securely

Y

No iqnition spark; distance of electrode
Air-pump failure piston faulty
Gauze in burner head clogged

-

Dirt in thermostat or valve seat

-

By-pass flame too small

-

be responsible

determined by

-10-

G. TROUBLESHOOTING THE REFRIGERATOR - ELECTRIC

SYMPTOM

CAUSE

NOTE: It will be noted in this guide that several causes can be responsible

for one effect.

The real cause or causes should be determined by
the process of elimination, investigating each possible cause, star­ting at the top of the guide and proceeding to the bottom.

Inadequate ventilation

Refrigerator not level
Defective heater, wrong voltage or type
Voltage not constant

Electric connections loose

Heater not inserted correctly in its pocket

Improper food storage

-

H

-

H

Thermostat incorrectly used

-

Improper storage of liquid and moist foods

-

Leaky cabinet seals
Infrequent cleaning of food compartment

H

Refrigerator shut off with closed door

-

-

r/

Unwrapped odorous food

-

-

H

fl

#

-

-

H

fl

-

-

Incomplete contact of the thermostat capillary tube

Thermostat charge lost

Refrigerator unit failure

Ambient temperature too low

12 Volt relay faulty

Ambient temperature too high

-ll-

A

8

c

13

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Fig. 1

Fig.

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-12

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-16 -

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-17-