Servicing; Combustion & Calibration; Electrical - Baxi Neta-tec Combi GA Range Installation & Servicing Instructions Manual

Flue Sampling
Point
Air Sampling
Point
Case Front Panel
Securing Screws
Condensate Trap
Gasket
Sump
Condensate
Drain Pipe
© Baxi Heating UK Ltd 2012
Case Front Panel
Fig. 43
Control Box removed
for clarity
Fig. 44

12.0 Servicing

12.1 Performance Safety Check & 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.
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
(check air inlet sample).
• The integrity of the boiler combustion circuit and relevant
seals as described in Section 12.2.
• The operational gas inlet pressure as described in Section
10.2.1 to 10.2.7 and the gas rate as described in 10.2.8.
• The combustion performance as described in 'Check the
Combustion Performance' (12.1.4 to 12.1.6 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 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
4. Set the boiler to operate at maximum rate as described in
Section 14.1.1 to 14.1.6.
5. Remove the plug from the flue sampling point, insert the
analyser probe and obtain the CO/CO
less than 0.004.
6. If the combustion reading (CO/CO 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 12.2) &
re-check.
• Perform the Combustion & Calibration functions (Section
14.0) & re-check.
• Replace the gas valve (Section 13.23) & re-check.
12.2 Annual Servicing - Inspection
1. Ensure that the boiler is cool.
2. Ensure that both the gas and electrical supplies to the
boiler are isolated.
3. Remove the screws securing the case front panel. Lift the
panel slightly to disengage it from the studs on top of the case
(Fig. 43) and hinge down the Control Box.
4. Disconnect the condensate drain pipe and unscrew the sump
from the bottom of the condensate trap assembly (Fig. 44).
Remove any deposits from the sump and trap. Clean as
necessary and replace the sump.
ratio)
2
ratio. This must be
2
31