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13 Fault Finding
NOTE:
Before trying to operate the boiler make sure that :
• All gas supply cocks are open and that the gas supply has
been purged of air.
• There is a permanent mains supply to the boiler.
• There is a heating demand from the external controls.
WARNING
Always isolate the boiler from the electrical supply before car-
rying out any electrical replacement work.
Always check for gas soundness after any service work.
Electrical Testing
Should there be any doubt about the voltage supply to any of
the components, it is possible to carry out a simple electrical
test.
Important: On completion of the Service/Fault Finding tasks
which have required the breaking and remaking of the electri-
cal connections the earth continuity, polarity, short circuit and
resistance to earth checks must be repeated using a suitable
multimeter.
To carry out the electrical test, gain access, as follows:
Hinge down the control box and unclip the rear cover to gain
access. Refer to the wiring diagram 13.1 and fault finding
charts, diagrams 13.2 to 13.6.