Dismantling and assembling water heater — VW

Note:

Draining and refilling with coolant => Page
82-83
.

Cap
Sealing ring
Cap fitting
Felt (petrol)
Removing => Fig.
1
Repairing => Fig.
2
Installing => Fig.
4

Felt (diesel)
Removing => Fig.
1
Repairing => Fig.
3
Installing => Fig.
4

Hose clip

Flame detector - G64
Removing and installing => Fig.
6
Checking => Fig.
7

Glow plug - Q6
Checking => Fig.
5

Connecting lead for glow plug
Burner head
Removing => Fig.
16
Installing => Fig.
17

Heat exchanger
Removing => Fig.
18
Installing => Fig.
19

Temperature sensor - N10
Removing => Fig.
8
Checking => Fig.
9

Cap
Overheating fuse - S24
Removing and installing => Fig.
10
Checking => Fig.
10

Metering pump - V54
Checking supply => Figs.
20
and
21

Spring
Intake silencer
Removing and installing => Fig.
15
Checking => Fig.
15

Combustion air blower - V6
Removing and installing => Fig.
13
Adjusting => Fig.
14

Combustion air adjustment screw
do not adjust!

Retainer
Felt (petrol)
Removing => Fig.
1
Repairing => Fig.
2
Installing => Fig.
4

Felt (diesel)
Removing => Fig.
1
Repairing => Fig.
3
Installing => Fig.
4

Recirculation pump - V55
Removing and installing => Fig.
12

O-ring
Series resistor - N6
Removing and installing => Fig.
11
Checking => Fig.
11

Connection for electrical wiring loom
=> Page
82-66

Fig.1
Removing felt

Remove retaining springs (can jump off).
Lever off cover using two screwdrivers in recesses -A-.

Fig.2
Repairing petrol heater felt

Sealing rings -A- and -B- must always be renewed.
Insert ring complete with felt until the ring recesses align with lugs on burner head.
Do not use adhesive to stick felt disc -c- in position.

Fig.3
Repairing diesel heater felt

Sealing rings -A- and -B- must always be renewed.
Insert ring complete with felt until the ring recesses align with the lugs in burner head.
Do not use adhesive to stick felt disc -c- in position.

Fig.4
Installing felt

When installing the cover, pay attention to marking -B-.

Fig.5
Checking glow plug (Q6)

Detach wire.
Remove glow plug.
At 12 V, the glow plug has a current draw of 20 A ± 10 %.
Carbon deposits should be removed by glowing and careful cleaning.
When installing, tighten to 30 Nm.

Fig.6
Removing and installing flame detector G64

Remove fillister head screw.
Pull flame detector out.
Detach wiring.
When installing, the O-ring -1- should be pushed onto the tip of the flame detector and then pressed into the drilling.
Secure flame detector with fillister head screw.
Pay attention to polarity when connecting up wiring (if necessary, use CFD).

Note:

Fragments of flame detector present in combustion chamber can remain there.

Fig.7
Checking flame detector (G64)

Switch on heater.
If after 30 secs. the heater switches to defect switch-off (without run-on) a short circuit is present in the wiring or in flame detector.
If after successful start heater switches off after 120 seconds and goes over to start repeat, but then after a total of 240 secs. switches to defect switch-off (without run-on), there is an interruption in the electrical wiring or a defect in the flame detector itself.

Fig.8
Removing and installing temperature sensor (N10)

Disconnect wires.
Unscrew temperature sensor.

Important

Before removing however, release pressure in cooling system by removing cap.
The temperature sensor must only be installed with an O-ring and tightened to 0.5 Nm.

Fig.9
Checking temperature sensor (N10)

The temperature sensor is a PTC resistance.
When checking the resistance as per diagram, a maximum measuring current of 1 mA must not be exceeded.

Fig.10
Removing and installing/checking overheating fuse (S24)

Disconnect wiring.
Check overheating fuse for continuity with an ohmmeter.

Important

Before removing, release pressure in cooling system by removing cap.
The overheating fuse, together with O-ring is screwed in by hand. One should ensure that the tip of the overheating fuse is in contact with the heater pipe (dimension a font=symbol charset=fontspecific code=64 descr='[ap]' 0.8 mm).

Fig.11
Removing and installing/checking series resistor (N6) for partial output

Remove heater cap.
Remove fillister head screw and separate connection.
Resistance value 3.3 ω ± 3 %.

Fig.12
Removing and installing recirculating pump (V55)

Mark all connections.
Separate connectors.
The pump can be taken off after slackening the clip -A-.
When installing the recirculating pump with the angled connection, insert into the heat exchanger and secure with clip -A-.
Renew O-ring -B-.

Note:

When connecting up the electrical wiring for recirculating pump, ensure that the wire colours are not interchanged, because otherwise the direction of rotation will be reversed (if necessary, refer to CFD).

Fig.13
Removing and installing combustion air blower (V6)

Remove intake silencer.
Mark connections.
Separate electrical connectors.
Remove screw -B- on blower.
Pull combustion air blower out.

Fig.14
Adjusting combustion air blower (V6)

The combustion air blower adjustment has been preset.

Note:

The adjusting screw -arrow- must not be moved.

Fig.15
Removing and installing/checking intake silencer

Unclip plastic strap -A- and retain for futher use.
Pull silencer off retainer -B-.
Check silencer for clear passage.

Fig.16
Removing burner head

Release pressure in heating system by opening radiator cap.
Disconnect water hoses on heater.
Remove clip.
Insert two screwdrivers in the recesses -B- and lever burner head out.
If dirty, clean all parts.

Fig.17
Installing burner head

Before installation, sealing paste Stucarit 203 must be applied between the burner head and heater pipe -C-.
Installation is carried out in the reverse order.

Fig.18
Removing heat exchanger

Remove temperature sensor and overheating fuse.
Remove burner head.
Using two screwdrivers, lever off the heat exchanger.
Combustion deposits should be cleaned off with a water jet and brush.

Fig.19
Installing heat exchanger

Apply sealing paste Stucarit 203 between burner head and heater pipe -C- before installation.
Installation is carried out in the reverse order.

Fig.20
Checking the metering pump (V54) output for petrol heater

For test sequence => Fig.
21
.

Fig.21
Checking metering pump (V54) output for diesel heater

Separate the glow plug 2-pin connector.
Pull fuel line off heater and insert it into a measuring cylinder (100 ml volume).
Using a voltmeter measure the voltage between contacts T 6/4 and T 2a/2.
Switch on heater after 90 secs. automatic defect switch-off occurs followed by start repetition.
Switch heater on again and measure fuel volume after 2 x 90 secs.
For evaluation, enter the data in the appropriate diagram => Fig.
20
or
21
.
The average output must be within the shaded area.