Dismantling and assembling heater unit -B2L- — VW

Upper heat shield
Upper outer cover
Removing:

Remove support plate -
24
-, remove bolts -
34
- on side of outer cover.
Take off outer cover.
Unclip sealing strip -
29
-.

Installing:

Fit sealing strip -
29
- on to lower outer cover.
Fit outer covers to one another and bolt together.
Ensure sealing strip seats perfectly.

Self-tapping screw B4.2x9.5
Use with silicone washer

Bolt M5x8
Use with silicone washer

Bracket
Hexagon nut M6
Spring washer
Bonded rubber mounting
Combustion monitor -F16-
The combustion monitor switches the glow spark plug -
28
- off after a stable flame has been established and also terminates the safety time period. The monitor also terminates the run-on when the heater unit has cooled.
Open at temperatures above 100 °C ±3 °C
Closed at temperatures lower than 90 °C ±4 °C
Replacing => Fig.
1

Heat exchanger
Note: Do not remove combustion chamber from heat exchanger

Clamp
Sealing ring
Always renew after dismantling

Combustion, fresh and heated air blower
Removing and installing => Fig.
4
Dismantling and assembling => Page
82-34

Electric motor for combustion, fresh and heated air blower -V81-
Removing and installing combustion, fresh and warm air blower => Fig.
4
Dismantling and assembling => Page
82-34

Temperature limiting switch -F82-
The temperature limiting switch switches the fuel pump off when outlet temperatures are above 125 °C.
Replacing => Fig.
2

Glow coil temperature switch -F153-
The glow coil temperature switch switches the glow spark plug glow coil off when the flame will operate from sparks alone in normal control mode.
Open at temperatures above
45 °C ±3 °C
Closed at temperatures lower than 25 °C ±4 °C
Replacing => Fig.
2

Sealing strip

Wiring distributor -T- (printed circuit)
The petrol electric heater wiring distributor is marked with a white "B".
Removing and installing => Fig.
5
Contact assignment:

=> Current flow diagrams, Electrical fault finding and Fitting locations

Temperature sensor -G18-
The heat output is dependent upon the setting of the temperature control switch and the temperature measured at the temperature sensor.
The temperature sensor is secured to the combustion, fresh and heated air blower.

Bolt M5x8
Lower outer cover
Note: Ensure 2 mm drilling in lower outer cover is clear and free of debris

Ignition transformer -N152-
Removing and installing => Fig.
5

Seal, black
Installing:

Ensure sealing strip is seated perfectly

Support plate
Self-tapping screw B4.2x13
Use with silicone washer

Glow plug wiring
Protective cap, black
Glow spark plug -Q5-
17 Nm

Sealing strip
Installing:

Coat with Vaseline.
Fit to lower outer cover.
Ensure sealing strip is seated perfectly.

Lower heat shield
Lower insulation plate
Installing:

Determine insulating plate position from previous plate and secure to heat shield using a silicone adhesive sealing compound.

Upper insulation plate
Installing:

Determine insulating plate position from previous plate and secure to heat shield using a silicone adhesive sealing compound.

Overheating switch -F17-
The overheating switch switches off the fuel supply when the maximum permitted heated air temperature is exceeded simultaneously the red malfunction warning lamp -K88- will flash in the temperature control switch.
Open at temperatures above 110 °C ±4 °C
Closed at temperatures lower than 95 °C ±4 °C
Replacing => Fig.
3

Self-tapping screw B4.2x9.5
Use with silicone washer

Fig.1
Replacing combustion monitor -F16-

Removing

Pull connectors off.
Release securing spring -1- with a screwdriver.
Take out intermediate piece -2- and combustion monitor -3-.

Installing

Ensure electrical wiring is not trapped between heat exchanger fins and heat shield.

Note:

Exchange securing spring with combustion monitor.

Fig.2
Replacing glow coil thermo switch -F153- and temperature limiting switch -F82-

1 -
Glow coil thermo switch -F153-
(white wiring)

2 -
Temperature limiting switch -F82-
(grey wiring)

Fig.3
Replacing overheating switch -F17-

1 -
Screw M3x10
2 -
Overheating switch -F17-
3 -
Insulating washer

Fig.4
Removing and installing combustion, fresh and heated air blower

Removing

Pull connectors -1- off overheating switch.
Pull connectors -2- off combustion monitor.
Pull electric motor wiring -3- off wiring distributor -4-.
Pull connectors -6- off glow spark plug.

Pull temperature sensor -G18- out of bracket on spiral housing -5-.

Lift combustion, fresh and heated air blower with heat exchanger up in direction of arrow until clamp is easily accessible.
Loosen clamp, pull blower off and remove sealing ring.

Installing

Coat outer cover in area of seal with vaseline.
Fit new sealing ring between blower and combustion chamber.
Fit blower on combustion chamber, install clamp and tighten lightly.
Press heater unit in lower outer cover.
Tighten clamp securely.
Secure temperature sender to spiral housing.
Reconnect connectors.

Fig.5
Removing and installing ignition transformer -N152- and wiring distributor -T- (printed circuit)

Pull connectors off glow spark plug -Q5-.
Remove screws -arrows-.
Take out ignition transformer -2- and wiring distributor -1-.

Dismantling and assembling combustion, fresh and heated air blower

Combustion air blower
Do not dismantle further

Blower wheel (for fresh and heated air)
Observe installation dimensions =>Fig.
1

Coupling
Installing:

Fit on electric motor shaft

Observe installation dimensions =>Fig.
1

Sealing strip
Replacing

Spiral housing (for fresh and heated air blower)

Electric motor for combustion, fresh and heated air blower -V81-
Screw M5x16
Bolt M4x8

Fig.1
Blower wheel and coupling installation dimensions

1 -
Electric motor for combustion, fresh and heated air blower
2 -
Coupling
3 -
Spiral housing
4 -
Threaded pin
Tightening torque 120 Nm±30

5 -
Blower wheel
6 -
Combustion air blower

Observe installation dimensions:

a -
1.4 mm ± 0.3
b -
4.0 mm ±1.0