13.0 Servicing
Case Front Panel
Fig. 73
Facia Panel Securing 
Screws
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.
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 11.2.7 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
•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/CO2 ratio. This must be less than 0.004.
6.If the combustion reading (CO/CO2 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 13.2) &
• Adjust the gas valve (Section 15.0) &
• Replace the gas valve (Section 14.24) &
Inner Door |
| 13.2 | Annual Servicing - Inspection | |
Fig. 74 |
|
| ||
Panel | 1. Ensure that the boiler is cool. | |||
| ||||
|
| 2. Ensure that both the gas and electrical supplies to the | ||
|
| boiler are isolated. | ||
|
| 3. Slacken the screws securing the facia panel. Lift the outercase | ||
|
| panel so that its securing tabs are clear of the facia. Remove the | ||
|
| panel, allowing the facia to hinge down (Fig. 73). | ||
|
| 4. Remove the screws securing the inner door panel. Lift the | ||
|
| panel slightly to disengage it from the studs on top of the case | ||
|
| (Fig. 74). |
| |
|
| Sump |
| |
|
| 5. Unscrew the sump from the bottom of the condensate trap | ||
|
| assembly (Fig. 75) and remove any deposits from the sump and | ||
|
| trap. Clean as necessary and replace the sump. | ||
|
| Fig. 75 |
| |
40© Baxi Heating UK Ltd 2012
