Potterton 24 Eco HE Installation & Service Instructions Manual page 45

15.0 FAULT FINDING
I
Ensure that mains input
terminal L is Live (230V) and N
is Neutral (0V)
YES
Check and correct if necessary
1. Flame sensing electrode and lead connections
2. Electrode position
Flame current should be 1 µA approx.
J
Boiler overheat thermostat
operated or faulty, i.e. continuity
across thermostat terminals
YES
K
Check terminal 1 of ON/OFF/RESET selector is in
connection with PCB - M1 connector terminal 16
Check electrical continuity across terminals 1 & a of
ON/OFF/RESET selector when turned to 'Reset' position
L
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. If the flue overheat thermostat has
not been activated see section 'D'
Publication No. 5111811
YES
NO
Allow to cool. Continuity
NO
across thermostat terminals
more than 1.5 ohm
Replace
PCB
Replace PCB
Replace flame sensing electrode
YES
NO
Replace ON/OFF/RESET selector
YES
Replace PCB
Replace boiler
overheat thermostat
45