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4000122704-1
18 Fault Finding
FAULT: NO HEATING
Is the heating set high enough ?
Is the room thermostat in demand ?
The setting is too low or the boiler
is set to summer mode.
Turn the setting up by turning the
central heating temperature
control knob clockwise.
NO
Adjust the setting.
NO
Check the thermostat, the line,
the connections both
to the room thermostat and
the control board (PCB).
YES
YES
Check by overriding the room thermostat
at the connector. Does the fault persist ?
YES
Check the electrical connections
to the control board (PCB).
If the problem persists fit a
replacement control board (PCB).
NO
Is the system fitted with
a external sensor ?
YES
YES
YES
Unplug the sensor
and test it individually.
