Dometic RM2551, RM2453, RM2552, RM2553, RM2554 User Manual

PROCEDURE FOR

®

CHANGING COOLING UNIT

IN CARAVAN 95 AND NDR

REFRIGERATORS

Refrigerator
Bulletin R74/6D
March 2002

The following categories have been established predicated on similarity of design and procedure for
replacement of cooling units:

A - CATEGORY #1

RM2193 RM2332 RM2333
RM2452 RM2453 RM2551
RM2552 RM2553 RM2554
RM4223 RM4290 RM4292

B - CATEGORY #2

RM2620 RM2652 RM2820
RM2852 RM3662 RM3663
RM3862 RM3863 NDR1062

C - CATEGORY #3

RM1272 NDR1282
RM1282 NDR1292
NDR1272 NDR1492

GENERAL INSTRUCTIONS TO ALL MODELS

1. Disconnect shore power from coach, the positive lead
from battery, and turn propane OFF at the tank.

These instructions must be read and under­stood before installation of this kit. This kit must
be installed by a Dometic service center or a
qualified service technician. Modification of this
product can be extremely hazardous and could
result in personal injury or property damage.

Important: After the cooling unit has been installed,

the initial start-up time can be shortened by tilting the
refrigerator from side-to-side and then from front-to­back before the refrigerator is turned on. Hold in each
tilt position for approximately 30 seconds to settle
solution to bottom of cooling unit.

2. Through lower vent, unplug refrigerator 120V AC cord(s)
from wall receptacle. Disconnect 12V DC wires from
terminal block on the refrigerator (if models have 12V
DC). Tape or cap ends.

3. Check again to make sure propane is OFF at tank, then
remove coach gas line from gas cock on refrigerator and
cap coach gas line.

4. For Models with Ice Maker: Turn water OFF to
appliance. Disconnect coach’s water line from water
solenoid (cap end).

5. Remove the refrigerator from alcove.

A. Category #1:

RM2193 RM2332 RM2333 RM4223
RM2452 RM2453 RM2551 RM4290
RM2552 RM2553 RM2554 RM4292

TILT FRONT-TO-BACK

TILT SIDE-TO-SIDE

Run the refrigerator on a bench for 12 hours after the cooling
unit has been installed. The refrigerator should not have food
in it during this test.

REVISION

Form No. 3107154.035 3/02
(Replaces 3107154.027)
©2002 Dometic Corporation
LaGrange, IN 46761

STEP 1. REMOVAL OF COOLING UNIT

1. See General Instructions on all models.

2. Loosen screws holding the thermostat bulb to fins. See
FIG. A1.

Note: Some models have a plastic thermistor bracket
clipped to the fin.

3. Remove the screws from the back wall of the freezer and
the fins.

Note: On models RM2452, RM2453, RM2551, RM2552,
RM2553 and RM2554, the fins are installed on the cooling
unit before it is put in the cabinet. The cooling unit must be
out of the cabinet before the fins can be removed.

4. On all other models remove the fins. See FIG. A1.

5. Lay the refrigerator face down on two 2x4’s to avoid
damaging the refrigerator front.

6. Remove cover from boiler and heating element(s).

7. Remove burner cover and then the burner assembly.

Note: Some models have a bracket that holds the manual
gas cock and/or the electric solenoid valve. Remove the
screws from these brackets and save to be reinstalled.

8. Cut the wire ties along the left side. Remove the
thermostat sensor tube (if required) and position the
burner assembly and wires so they will not be damaged

1

by pulling the cooling unit.

STEP 2. INSTALLATION OF COOLING

UNIT

1. Inspect cooling unit for broken welds or bent frame.

2. Trim the foam block portion of cooling unit if it does not
go freely into the refrigerator. Be sure foam does not
cover the evaporator tubes where cooling fins attach.

3. Apply thermomastic on evaporator tubes 1/4” to 3/8”
bead. Apply more if the tubes are recessed in foam
block. (FIG. A3)

4. Apply permagum and double-stick tape to cabinet as
shown in FIG. A4.

FIG. A1

5. If foam block fits loosely into cabinet (1/4” or more of
movement) use 1/2” wide x 3/8” thick closed cell, one­sided adhesive weather stripping. Place in the same
location as permagum. Also apply double-stick tape as
shown in FIG. A4.

6. Install cooling unit back in the cabinet. Replace screws
holding cooling unit to cabinet. Replace components
removed in Step 1, 587. (FIG. A2)

7. Stand refrigerator upright. Transfer flue baffle to new
cooling unit. Replace the inside parts removed in Step 1,
2–4. (See “Important” on Page 1).

8. Install refrigerator back into coach and leak check all gas
fittings. Repair all gas leaks.

Do not use a flame

to check for gas leaks.

FIG. A3

FIG. A2

FIG. A4

2

B. Category #2

RM2620 RM2652 RM2820 RM2852
*RM3662 *RM3663 *RM3862 *RM3863
*NDR1062

* Optional Ice Maker Cycle

STEP 1. REMOVAL OF COOLING UNIT

1. See General Instructions for all models.

2. Remove thermistor bracket and 4 screws from fins (FIG.
B1). DO NOT remove fins. They are taped to the rear of the
cabinet liner.

3. In the freezer, remove shelves and grill covering screws.
Pull out center of grill to allow right or left side to pop out
of slot (FIG. B1).

4. Models with Ice Maker: Remove the cover of cycle and
the 2 screws holding cycle to the side wall (FIG. B2).

5. Remove 4 screws holding cycle bracket. Be careful not to
drop. Unplug electrical connection and take cycle out of
freezer. Remove the remaining screws. (FIG. B2)

6. Lay the refrigerator face down on two 2x4’s to protect the
face of the appliance.

7. Remove heater cover and heater(s) (FIG. B3 & B4). Also
disconnect ice wire harness leads from electrical connec­tions on the refrigerator.

Note: NDR models - pull wire harness out of the cooling unit
from the inside of freezer. Pull water fill tube from rear of
refrigerator. Disconnect water line from water solenoid valve.

8. Remove burner cover (1 screw) and screw holding the
burner to flue tube. Pull burner down and off tube (FIG. B4).

9. Remove 2 screws holding control panel to runner and 2
screws holding gas solenoid valve to cooling unit (FIG. B4).

10. Take out screws (1 on each side) where runner fastens to
the rear of cabinet. Swing runners out to the side to clear
cabinet (FIG. B3).

11. Cut wire ties holding cables and thermistor to frame of
cooling unit.

12. Disconnect climate control and interior (red wires) from J2
on circuit board and black wires from ground.

13. Cut red and black wires from interior light. Strip back 3/8”
to reconnect using butt connectors after cooling unit has
been installed.

14. Remove 4 screws holding cooling unit to cabinet (2 on top
and 2 on bottom). (FIG. B3). Lift cooling unit out of cabinet.

FIG. B1

FIG. B2

FIG. B3

STEP 2. INSTALLATION OF COOLING UNIT

1. Refer to Step 2, Category A, 1–5.

2. Install cooling unit back in cabinet. Replace screw holding
unit.

3. Replace the components removed in Step 1, 2-14.

4. Stand refrigerator upright. Transfer the flue baffle to new
cooling unit. Replace inside parts removed in Step 1, 2–5.

5. Check for proper cooling before installing refrigerator back
into the coach. (See “Important” on Page 1).

6. Install refrigerator back into coach and leak check all gas
fittings. Repair all gas leaks.

Do not use a flame

to check for gas leaks.

FIG. B4

3