Auxiliary Cabin Heater Control Module: Service and Repair

AR83.70-P-5935C Remove/Install Control Module/Heat Exchanger Unit
- with CODE (228) Stationary heater







Remove
1 Remove burner element
2 Remove screws (1)
3 Disconnect burner housing (2) from the heat exchanger (4)

NOTE: The heat exchanger (4) and STH control module or heater booster (A6n1) form a unit.

4 Pull the vent hose (5) out of the vent drill hole (6) on the heat exchanger (4)

NOTE: If installed.

5 Remove sealing rings (3) from the heat exchanger (4) housing
6 Remove sealant from the heat exchanger (4) and the burner housing

Install
7 Insert sealing rings (3) into the seats on the heat exchanger (4) housing

NOTE: Use new seal rings.

8 Coat sealing surfaces on the heat exchanger (4) housing and on the burner housing (2) with sealant

9 Position burner housing (2) on heat exchanger (4) and insert screws (1)

CAUTION: Use new bolts. Coat the screw threads with locking compound.

10 Guide the vent hose (5) through the vent drill hole (6) into the heat exchanger (4).

NOTE: If present.

11 Tighten screws (1)
- Stationary heater burner housing screw: 4 N.m

12 Remove sealant which has escaped from the area of the joint
13 Install burner element
14 Check emission level, adjust if necessary.