Servicing - Baxi 47 075 35 Installation & Servicing Instructions Manual

page 37
13.0 Servicing
13.1 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. 7967­4.
2. After servicing, complete the relevant Service Interval Record section of the Benchmark Commissioning Checklist at the rear of this
publication.
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 complete flue system and the flue seals.
The integrity of the boiler combustion circuit and relevant seals as described in Section 13.2.
The operational gas inlet pressure as described in Section 11.2. 1 to 7 and the gas rate as described in
11.2. 8.
The combustion performance as described in 'Check the Combustion Performance' (13.1.4 to 13.1.6
below).
3. 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 BS­EN50379­3 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 (CO/CO2 ratio)
4.
Set the boiler to operate at maximum rate as described in Section 15.1.1 to 15.1.6.
5.
Remove the plug from the flue sampling point, insert the analyser probe and obtain the CO/CO
This must be less than 0.004.
6.
If the combustion reading (CO/CO
system
and combustion circuit seals has been verified, and the inlet gas pressure and gas rate are satisfactory
either:
Perform the 'Annual Servicing ­ Inspection' (Section 13.2) & re­check
Adjust the gas valve (Section 15.0) & re­check
Replace the gas valve (Section 14.23) & re­check
ratio) is greater than this, and the integrity of the complete flue
2
ratio.
2