Technical data

29
© Baxi Heating UK Ltd 2014
8.0 Annual Servicing
Off Position
Fig. 49
On Position
Fig. 50
8.1 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 complete flue system and the flue seals.
• The integrity of the boiler combustion circuit and
relevant seals as described in Section 8.2.
• The operational gas inlet pressure as described in Section
7.3.1 to 7.3.3 and the gas rate as described in 7.3.4.
• The combustion performance as described in ‘Check the
Combustion Performance’ (8.1.6 to 8.1.8 below).
5. 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 (CO/CO
2
ratio)
6. Set the boiler to operate at maximum rate as described in
Section 10.1.2 to 10.1.6.
7. 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.
8. If the combustion reading (CO/CO
2
ratio) is greater than
this, and the integrity of the complete flue 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 8.2) &
re-check
• Adjust the gas valve (Section 10.0) & re-check
• Replace the gas valve (Section 9.8) & re-check or contact
the ‘heateam’ Technical Helpline (0844 871 1555).
Flue Sampling
Point Plug
Electrical Test Point
This test point must be used to confirm complete isolation of the
appliance if a Service Inspection is to be performed (Section 8.2).
From left to right the terminals are Switched Live, Live, Neutral and
Earth. With the Mains Input Plug removed, check using a suitable
multimeter.
Fig. 48
Air Sampling
Point