Fault Finding - IDEAL Concord CXA 40/H Installation & Servicing Manual

Before attempting any electrical fault finding ALWAYS carry out
the preliminary electrical system checks as detailed in the
Instructions for the British Gas Multimeter or other similar
commercially available meter.
The preliminary electrical system checks are the FIRST
electrical checks to be carried out during a fault finding
procedure.
On completion of any service/fault finding task which has
required the breaking and remaking of electrical connections
the following checks MUST be repeated:
46 PILOT WILL NOT LIGHT
Is there a spark at the ignition electrode ?
Is there gas at the pilot burner ?
YES
Pilot should
now light
47 PILOT WILL NOT STAY LIT
Is the detection electrode, its lead and
connections clean, tight and undamaged ?
Is the pilot flame of the correct length ?
Check flame current; expect 1.5 µ A
Faulty PCB S4561B1054 - replace
28

FAULT FINDING

YES
NO
Allow time to purge any air
present.
Ensure that there is gas
pressure at the boiler
inlet. Check that the pilot jet
is not blocked.
YES
YES
YES
a Earth continuity
b Polarity
c Resistance to earth
Detailed instructions on the replacement of faulty components
are contained in the 'Servicing' section of these Installation &
Servicing Instructions.
Before carrying out Fault Finding ensure that all external controls
calling for heat and the overheat thermostat has not operated.
There should be 230V +- 10% available at the control box
connection.
NO
Check that the gap between the electrode
pilot burner is 3-4 mm.
Ensure that the H/T lead and electrode are
sound, clean and undamaged and that the
YES
connections are secure.
Check that the spark generator is operative
by carefully holding an earthed screwdriver
3mm from the H/T output terminal of PCB
S4561B1054 in the control box with the
ignition lead removed and then switching
Is there a spark ?
Faulty PCB S4561B1054 -
NO
Clean or replace.
Is inlet pressure satisfactory ?
NO
Is pilot burner, injector and pipe clean and
undamaged ?
NO
Check earth connections
Concord CXA/H
and
the boiler on.
NO
replace
- Installation and Servicing