10 Maintenance
10.1 General
10 Maintenance
62
Warning
When changing components ensure that both the gas and electri
cal supplies to the boiler are isolated before any work is started.
When the component has been changed recommission the boiler.
Always examine any seals or gaskets, replacing where necessary.
The case front panel MUST seal effectively against the boiler side
panels.
Warning
After servicing or performing any maintenance on the boiler en
sure that
Both flue test point plugs are in place
The front cover is correctly fitted
The front cover securing screws are fully tightened
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 BS 7967-4.
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 by checking
air inlet sample to eliminate the possibility of recirculation. O
2
≥ 20.6% &
CO
2
< 0.2%
The integrity of the boiler combustion circuit and relevant seals.
The operational gas inlet pressure and the gas rate.
The combustion performance as described in "Check the Combustion
Performance" below.
Competence to carry out checking combustion performance BS 6798
"Specification for Installation & Maintenance of Gas Fired Boilers not ex
ceeding 70kWh" 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 inter
pretation of the results.
The flue gas analyser used should be one meeting the requirements of
BS 7927 or BS-EN50379-3 and be calibrated in accordance with the an
alyser 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/CO
2
ratio) Set the boiler to
operate at maximum rate.
See
Checking combustion - chimney sweep mode, page 49 for details.
Combi 2
