Servicing additional water heater -B7W/D7W- — VW

Warning!
Always disconnect the battery earth strap before working on the electrical system.
Note:

Before disconnecting battery obtain radio anti-theft coding.
B7W: Petrol electric water heater
D7W: Diesel electric water heater
A manufacturer's plate is attached to the heater unit. This plate gives details of heater unit type installed in vehicle =>Fig.
1
.

Removing and installing heater unit components => Page
82-210
; dismantling and assembling heater unit.
After working on coolant circuit check coolant circuit

=> relevant engine assembly group, mechanics; Repair group 19
relevant engine assembly group, mechanics

Thermo switch -F80-
Opens at an engine coolant circuit temperature of 55 °C.
Connects engine circuit to heater circuit via coolant shut-off valve -N82-. Further notes => Page
82-227
; connecting water heater into coolant circuit.

Fresh air blower relay -J13-
Behind dash panel, right
The fresh air blower -V2- is switched to the 2nd stage when the coolant temperature in the heater circuit reaches 55 °C.
Removing and installing => Fig.
2

Resistance wire relay -J116-
Behind dash panel, right
Protects glow plug for heater -Q9- from excessive voltage with ignition switched on.
Removing and installing => Fig.
2

Heater control unit -J162-
Behind dash panel, right
Removing and installing => Fig.
2

Pre-selection clock -E111-
Removing => Fig.
3
Operation and function => Page
82-205

Note:

The water heater can only be switched on when the temperature selection lever, on the heated air and fresh air controls, is pushed completely to the right.

Heater switch on -F102-
On the heated air and fresh air controls
Removing and installing => Fig.
4

Fuse carrier
Under driver's seat
Fuse assignment =>Fig.
5

Fuel pump -G23-

Note:

The B7W and D7W water heater fuel pumps have differing outputs: Observe part number.

Removing and installing => Page
82-238
; water heater fuel supply
Checking quantity delivered => Fig.
15

Exhaust system
Removing and installing => Fig.
6
Securing exhaust pipe to heater unit => Fig.
7

Heater unit
Removing and installing => Fig.
8
Dismantling and assembling => Page
82-210

Coolant distributor
With non-return valve
Coolant hose routing => Page
82-227
; connecting water heater into coolant circuit

Fig.1
Manufacturer's plate

Notes:

Only versions 20168105 or 25171405 are installed by manufacture in Transporter 1991▸ .
Water heaters with other version numbers are repaired by authorized Eberspächer workshops.

Fig.2
Removing and installing heater control unit -J162-, resistance wire relay -J116- and fresh air blower relay -J13-

1 -
Heater control unit
2 -
Resistance wire relay
3 -
Fresh air blower relay

Removing

Remove glove compartment.
Remove assembly plate (carrier for control unit and relay) -arrows-.
Pull off connectors to control unit.
Take assembly plate out.

Fig.3
Removing pre-selection clock -E111-

Carefully lever pre-selection clock out from trim with a screwdriver -arrows-.
Pull connector off.

Fig.4
Removing and installing heater switch on -F102-

Remove heated air and fresh air controls -1-

=> Heater, air conditioner; Repair group 80; Servicing heating
Heater, air conditioner
Servicing heating

Remove switch -2- from controls.

Fig.5
Fuse assignment on fuse carrier under driver's seat

1 -
Glow plug fuse -S66-
2 -
Heated air blower fuse -S25-
3 -
Heater fuse -S23-

Fig.6
Removing and installing exhaust system

1 -
Exhaust pipe
2 -
Silencer
3 -
Pop rivet
4 -
Silencer bracket
5 -
Hose clamp
6 -
Self-tapping screw
7 -
Exhaust pipe to heater unit
8 -
Clip
9 -
Self-tapping screw

Notes:

The exhaust pipe -7- is to be routed so as not to touch the starter wiring (danger of short circuit). Further notes => Fig.
7
.
The exhaust pipe -1- and the silencer -2- are gradually being replaced by a new component (exhaust pipe and silencer are welded to one another).
On vehicles with foglights the exhaust pipe -1- must be a distance of at least 20 mm from the foglight.

Fig.7
Securing exhaust pipe to heater unit

The exhaust pipe -1- is pushed in direction of arrow until it contacts the combustion air blower bracket -2-.

Fig.8
Removing and installing heater unit

1 -
Exhaust pipe insulation hose
(gradual introduction: exhaust pipe with insulation covering)

2 -
Fuel pipes
3 -
Hexagon nut
4 -
Bonded rubber mounting
5 -
Hexagon bolt
6 -
Bracket
7 -
Exhaust pipe to silencer
8 -
Pop rivet
9 -
Longitudinal member

Removing

Fold radiator and lock carrier out forwards.
Remove insulation tray.
Open radiator cap.
Clamp coolant hoses at heater unit.
Pull 12 pin connector off -T12-.
Disconnect exhaust pipe at heater unit.
Disconnect and seal fuel pipes at heater unit.
Unbolt heater from bracket and remove.

Installing

Install in reverse order.
After installing bleed coolant circuit.

Operation and functions of pre-selection clock -E111-

1 -
Memory number display (1, 2 or 3)
2 -
Time/pre-selected time display
3 -
Flash code display
The flash code display gives information about the momentary heater operation condition.

4 -
Temperature display
5 -
"Heater on" display
6 -
Weekday display
7 -
Time button
8 -
Memory selection/day button
9 -
"Heater on"/"heater off" button
10 -
Re-selecting time or pre-selected time and calling up remaining time button
11 -
Re-setting time or pre-selected time, setting pre-selected day and temperature display

Notes:

The heater will operate for max. 30 minutes with ignition switched off.
With the ignition switched on a continuous operation is possible. If the ignition is then switched off the heater will operate for a further 5 minutes and then enter the run-on phase.
A maximum of three different pre-selected times can be set.

Switch on point can be preset for up to one week.
Pre-selected times remain in the memory and can be reactivated.

Setting time

Press and hold button -7-.
Set correct time with buttons -10- or -11-.

Setting weekday

Press and hold button -7-.
Set day with button -8-.

Switching heater on

Press button -9-.
The symbol for "heater on" -5- appears on display.

Switching heater off

Press button -9-.
The symbol "heater on" -5- disappears from display.

Note:

After switching off the heater the circulation pump -V55- and the combustion air blower -V6- will continue operate for two minutes.

Calling up or reducing remaining running time

Only possible in "heater on" mode.
Calling up remaining running time: Press button -10- briefly.
Reducing remaining time: Press and hold button -10- until the required remaining running time appears on the display.

Setting and activating pre-selected times

Using the pre-selected time button -8- the three possible pre-selected times and the actual time can be displayed one after the other.
The required pre-selected time can be set for each memory number by using button -10- or button -11-.

After a couple of seconds the weekday display -6- flashes and the required day can be set using button -11-.
If no further buttons are operated then the entry will be memorised after approx. 15 seconds. With the ignition switched on the display reverts to time of day and with ignition switched off the display disappears.
A pre-selected time -1- figure 1, 2 or 3 will remain on the display if a pre-selected time has been activated.

Cancelling activation

Press pre-selected time button -8- until the display -1- shows no figures.

Switching temperature display on

Note:

The pre-selection clock is not equipped with a temperature sensor. Therefore an incorrect value will appear on the display, for approx. 10 seconds, if button -11- is pressed with the ignition switched off.

The relevant temperature sensor can be connected to the pre-selection clock -E111- at contact 1 and 2 to enable the temperature display to be utilised (Eberspächer order No. 201 689 800 700).

With ignition switched off press button -11- and the temperature will be displayed for approx. 10 seconds.
The temperature will be displayed continuously with ignition switched on. Press time button -7- to return display to time of day.