Benchmark Commissioning Checklist - Keston 30C Installation And Servicing Instructions

43 SERVICING SCHEDULE
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will be able to download the relevant information.
WARNING. Always turn OFF the gas supply at the gas service cock, and switch OFF and disconnect the electricity
supply to the appliance before servicing.
Combustion testing must be carried out by a competent person using a combustion analyser conforming to BS7927.
To ensure the continued safe and efficient operation of the appliance it is recommended that it is checked at regular intervals
and serviced as necessary. The frequency of servicing will depend upon the installation condition and usage but should be
carried out at least annually.
It is the law that any service work must be carried out by a Gas Safe Registered Engineer. In IE service work must be carried
out by a Registered Gas Installer (RGII).
INSPECTION
1. Light the boiler and carry out a pre-service check, noting any
operational faults.
2. Check the flue terminal (and terminal guard if fitted) is
undamaged and clear of any obstruction.
3. Check all water and gas joints for signs of leakage. Remake any
suspect joints ensuring a gas tightness check is carried out if
applicable and the water system is correctly refilled, vented and
re-pressurised.
CLEANING PROCEDURE
Note. In order to carry out either servicing or replacement of
components the boiler front panel must be removed. Refer to
Frame 44.
1. Clean the main burner. Refer to frame 46.
2. Clean the heat exchanger & condensate trap/siphon. Refer to
Frames 47 & 48.
3. Check the main injector for blockage or damage. Refer to Frame
45.
4. Check that the flue terminal is unobstructed and that the flue
system is sealed correctly.
ALSO IF THE DHW FLOW RATE IS IN QUESTION :-
5. Check the DHW filter for blockage. Refer to Frame 74.
The cleaning procedures are covered more fully in Frames 45-50
and MUST be carried out in sequence.
IMPORTANT.
6. After completing the servicing or exchange of components
always test for gas tightness.
7. When work is complete the front panel MUST be correctly refitted,
ensuring that a good seal is made.
Do NOT OPERATE the boiler if the front panel is not
fitted.
8. If, for any reason, the condensate trap/siphon has been removed
ensure the trap is refilled with water before
reassembling.
9. Check the gas consumption.
10. Check combustion by connecting the flue gas analyser to the flue
gas sampling point as shown in the diagram and measure CO &
CO .
2
If the CO/CO ratio is greater than 0.004 AND the integrity of the
2
complete flue system and combustion circuit seals have been
verified and the inlet gas pressure (and gas rate) have been
verified, then contact Keston.
11. Complete the service section in the Benchmark Commissioning
Checklist.
44
SERVICING
GENERAL
Please Note : During routine servicing, and after any
maintenance or change of part of the combustion
circuit, the following must be checked:
- The integrity of the flue system and the flue seals,
- The integrity of the boiler combustion circuit and
the relevant seals
- The operational (working) gas inlet pressure at
maximum rate.
- The gas rate
- The combustion performance.
COMPETENCE TO CARRY OUT THE CHECK OF
COMBUSTION PERFORMANCE
Please Note : BS 6798:2009 Specification for
installation and maintenance of gas-fired boilers of
rated input not exceeding 70kW net 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, and
- 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 BS7967, Parts 1 to 4.
Flue Sampling Point
Keston 30C -
Installation and Servicing