Baxi Potterton BBU 15 HE - Manual (Page 27)

27
© Baxi Heating UK Ltd 2009
9.0 Annual Servicing
Off Position
Fig. 41
On Position
Fig. 42
9.1 Annual Servicing
1. For reasons of safety and economy, it is recommended that
the boiler is serviced annually. Servicing must be performed by
a competent person in accordance with B.S. 7967-4.
2. After servicing, complete the relevant Service Interval
Record section of the Benchmark Commissioning Checklist at
the rear of this publication.
3. Disconnect the firefront electric supply. Remove the fascia
from the firefront. Unhook its hanging brackets from the slots
in the top of the firefront. On Classica and Innova models also
disengage the retaining magnets at the lower part of the fascia.
4. Slacken the firefront retaining wire and unthread it from the
bracket on top of the boiler. The firefront can now be
manoeuvred away from the boiler. Do not drag the firefront
as it may damage the hearth. To completely remove the
firefront disconnect the boiler control cable.
IMPORTANT: During routine servicing, and after any
maintenance or change of part of the combustion circuit, the
following must be checked:-
The integrity of the flue system and the flue seals, as
described in Section 7.2.
The integrity of the boiler combustion circuit and relevant
seals as described in Section 9.2.
The operational gas inlet pressure as described in Section
8.2.14 to 8.2.16 and the gas rate as described in 8.2.17.
The combustion performance as described in 9.1.5 to 9.1.6.
Competence to carry out checking Combustion
Performance
B.S. 6798 ‘Specification for Installation & Maintenance of Gas
Fired Boilers not exceeding 70kW’ advises that:-
The person carrying out a combustion measurement
should have been assessed as competent in the use of a
flue gas analyser and the interpretation of the results.
The flue gas analyser used should be one meeting the
requirements of BS7927 or BS-EN50379-3 and be
calibrated in accordance with the analyser manufacturers’
requirements.
Competence can be demonstrated by satisfactory
completion of the CPA1 ACS assessment, which covers
the use of electronic portable combustion gas analysers in
accordance with BS 7967, Parts 1 to 4.
Check the Combustion Performance
5. Set the boiler to operate at maximum rate as described in
Section 11.1.2 to 11.1.6.
6. Remove the threaded plug from the sampling point, insert
the analyser probe and obtain the CO/CO
2
ratio. This must
be less than 0.004.
7. If the combustion reading is greater than this, and the
integrity of the flue system and combustion circuit seals has
been verified, and the inlet gas pressure and gas rate are
satisfactory either adjust the gas valve (Section 11.0), replace
the gas valve (Section 10.8) or contact the ‘heateam’ Technical
Helpline (0844 871 1555).
Flue Sampling
Plug