SERVICING AND SPARES
6 720 815 725 (2015/05)
38
6
SERVICING AND SPARES
6.1
INSPECTION AND SERVICE
• To ensure the continued efficient operation of the appliance it must
be checked at regular intervals.
• The frequency of servicing will depend upon the particular
installation conditions and usage. However, an annual service is
recommended.
• The extent of the service required by the appliance is determined by
the operating condition of the appliance when tested by
fully
qualified engineers.
• The service interval record sheet at the rear of these instructions
must be completed after each service.
INSPECTION
1. Check that the terminal and the terminal guard, if fitted, are clear and
undamaged.
2. If the appliance is in a compartment or cupboard check that the
specified service space around the appliance is clear.
3. Check all the joints and connections in the system and remake any
that show signs of leakage. Refill and re-pressurise if applicable as
described in Commissioning.
▶ Operate the appliance and make a note of any irregularities. Call up
the last fault stored by the Bosch Heatronic, press the Service button
and select Service Function
6.A
.
Use the ECO and Holiday buttons to scroll through the menu.
Refer to Fault Finding for rectification procedures.
6.1.1
CHECKING FLUE INTEGRITY
The integrity of the flue system and performance of the boiler can be
checked via the flue turret sample points.
Fig. 59 Flue turret test points
With the boiler case on and the boiler running at maximum output (refer
to paragraph “SET THE BOILER TO MAXIMUM”, page 39).
▶ Ensure that the probe reaches the centre of the air intake, adjust the
cone on the probe so that it seals the sample point and correctly
positions the end of the probe.
▶ Insert the analyser probe into the air intake sample point.
▶ Allow the readings to stabilise and check that:
– O
2
is equal to, or greater than 20.6%.
– CO
2
is less than 0.2%
▶ If the readings are outside these limits then this indicates that there
is a problem with the flue system or combustion circuit, e.g. missing
or dislodged seals.
Fig. 60 Flue integrity test
CAUTION:
TURN OFF THE GAS SUPPLY AND ISOLATE
THE MAINS SUPPLIES BEFORE STARTING ANY WORK
AND OBSERVE ALL RELEVANT SAFETY PRECAUTIONS.
NOTICE:
After replacement of any components always
check for gas tightness where relevant and carry out
functional checks as described in the commissioning
section.
Any O-rings and gaskets must be replaced.
NOTICE:
SERVICE MUST
NOT
BE ATTEMPTED IF A
CALIBRATED CO/CO
2
ANALYSER AND MANOMETER
ARE
NOT
AVAILABLE.
NOTICE:
Any service work must be carried out by
competent registered engineers such as British Gas or
Gas Safe registered engineer.
Please refer to the Service Record at the rear of the
manual.
Flue gas sample point
1
Air inlet sample point
2
Table 12 Key to figure 59
2
1
2
2
1
1
6720643895-67.1Wo
6720809056-3.1W
o
1
