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© Baxi Heating UK Ltd 2007
16.0 Fault Finding
Check and correct if necessary
1. Flame sensing electrode and lead connections
2. Electrode position
Flame current should be 1 μA approx.
Replace PCB
Replace PCB
YES
YES
Replace flame sensing electrode
NO
YES
Ensure that mains input terminal L
is Live (230V) and N is Neutral
(0V)
I
Check terminal 1 of ON/OFF/RESET selector is in
connection with PCB - A4 connector terminal 2
Check electrical continuity across terminals 1 & a of
ON/OFF/RESET selector when turned to ‘Reset’ position
Replace ON/OFF/RESET selector
NO
Replace PCB
YES
K
Replace safety
thermostat
YES
NO
Overheat thermostat operated or
faulty, i.e. continuity across
thermostat terminals
Allow to cool. Continuity
across thermostat terminals
more than 1.5 ohm
J
If checks in section I are completed successfully, blockage
of the condensate drain or trap may have occurred
L
If checks in section J are completed successfully, the flue
overheat thermostat may have operated. Press the reset
button on the flue overheat thermostat. If the boiler does
not relight or repeatedly cuts out. Check the operation of
the flue system or replace the flue overheat thermostat
M