Routine Servicing - Alpha CD25C Installation And Servicing Instructions

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ROUTINE SERVICING

To ensure efficient operation of the boiler it is recommended that it is checked and serviced as necessary at regular intervals.
The frequency of servicing will depend upon the particular installation conditions and usage, but in general once per year
should be adequate.
It is the law that any service work must be carried out by a competent person, i.e. CORGI registered personnel.
Warning: Before servicing the boiler, isolate the electrical supply and close the boiler gas service cock. Allow the boiler to cool.
The data label is positioned on the inside of the left hand side panel.
Always test for gas soundness after servicing any gas carrying components.
Always carry out electrical system checks i.e. Eart Continuity, Resistance to Earth, Short Circuit and Polarity with a suitable
meter after servicing.
Notes: 1. Prior to servicing, it is recommended that a flue gas analyser is used to measure the performance of the boiler (refer
to Fig. 2 for the position of the flue sampling point). If the CO/CO
other checks and comments from the customer have indicated that there may be problems, cleaning of the heat
exchanger will be necessary. All Sections 7.1, 7.2, 7.3 and 7.4 must be carried out. Repeat the flue gas analyser
test after reassembling the boiler and check that the CO/CO
2. If the CO/CO ratio measured is less than 0.002 and other checks and comments from the customer suggest there
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are no problems then only Section 7.1 and Section 7.2 paragraphs 1, 2 and 3 need to be carried out to allow a
visual check of the components within the room sealed chamber.
3. If a flue gas analyser is not available, then all Sections 7.1, 7.2, 7.3 and 7.4 must be carried out.
7.1 IMPORTANT NOTES PRIOR TO SERVICING
1. Check the flue terminal outside and ensure it is not blocked.
2. Run the boiler and check the operation of its controls.
3. Refer to Fig. 2 for location of flue sampling point.
4. Ensure that all system connections and fittings are sound. Remake any joints and check the tightness of any fittings that
may be leaking.
5. It is recommended that the operation of the safety valve is checked by turning the head anti-clockwise until it clicks. The
click is the safety valve lifting off its seat allowing water to escape from the system - check that this is actually happening.
6. Refill, vent and re-pressurise the system as necessary. (Refer to Commissioning, Section 5.1).
If the system pressure exceeds 2.5 bar when operating at maximum temperature, the heating expansion vessel should be
checked and re-pressurised, if necessary.
Notes: 1. Check the expansion vessel charge only when the system pressure is zero.
2. The expansion vessel pressure test point is accessible from inside the boiler at the top.
7. Check that the condensate trap drain pipe is connected and all joints are sound.
8. Record details of the service in the Service Record Section on page 39.
Front case locating pins
Front case fixing screws
ratio measured is greater than 0.002 or when
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ratio is less than 0.002.
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Combustion
chamber front
assembly
Gas pipe
union
Fan
assembly
Fan assembly
fixing screws
Fig. 26
Alpha CD25C/28C/35C - Routine Servicing
Six nuts and washers
securing combustion
chamber front
assembly
Viewing window
Pressure tube
connections
Ignition generator
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