Bosch WR8/11 G Series, Installation And Operating Istructions

6 720 607 845 (2015/05)

14 | Maintenance (must be carried out only by qualified technicians)

7.1

Periodic maintenance work

Functional check

▶ Check the operation of all safety, adjustment and 

monitoring elements.

Heat exchanger

▶ Check the heat exchanger is clean.
▶ In  case  of  dirt:

– Remove the heat exchanger and take out the limiter.
– Clean the chamber with a powerful jet of water.

▶ If dirt persists: Soak the plates in hot water with detergent 

and clean thoroughly.

▶ If necessary: De-lime the interior of the heat exchanger and 

the connection pipes.

▶ Install the heat exchanger using new joints.
▶ Install the limiter on the support.

Burner

▶ Check the burner annually and clean it if necessary.
▶ If it is very dirty (grease, soot): Remove the burner, soak it 

in hot water with detergent and clean it thoroughly.

Water filter

▶ Replace the water filter installed in the water valve entry.

Burner and pilot injector

▶ Remove and clean the pilot burner.
▶ Remove and clean the pilot injector.

7.2

Startup after maintenance work

▶ Tighten all connections once more.
▶ Read chapter 3 “Use” and chapter 6 “Adjustments”.

7.3

Flue gas safety device

Operation and safety precautions

The flue gas safety device checks the effectiveness of flue gas 
extraction by the flue. If it is inadequate, the appliance switches 
off automatically so that the combustion fumes do not escape 
into the room in which the appliance has been installed. The 
flue gas safety device resets after a cooling-down period.

If the appliance shuts down while in operation:
▶ ventilate the room.
▶ Wait about 10 minutes then restart the appliance.

 If the problem recurs, call an engineer.

Maintenance

If faults occur on the flue gas safety device, proceed as follows:
▶ Undo flue gas safety device fixing screw.
▶ Loosen temperature limiters connectors.
▶ Undo magnetic unit connector.
▶ Remove thermocouple.
▶ Replace damaged component with new one and refit using 

the reverse of the procedure set out in the table above.

Function check

Flue gas safety device function check:
▶ Disconnect flue pipe;
▶ Replace with pipe (about 50 cm long) with sealed end;
▶ Fit  pipe  vertically;
▶ Start up appliance at rated output and set temperature 

control to maximum temperature;
Under those conditions, the appliance should shut down 
after two minutes. Remove temporary pipe and reconnect 
flue pipe.

WARNING: 

Is forbidden to start up the appliance without 
water filter correctly assembled.

DANGER: 

The flue gas safety device must not under any 
circumstances be switched off, simulated or 
replaced by any other component.

DANGER: 

The user must never make any modifications 
to the flue gas safety device.