Potterton Promax SL range Installation & Service Instructions Manual page 58

OVERHEAT LOCKOUT
Disconnect
black stat on flow pipe.
When flow < 60° C is there
continuity across stat ?
YES
Reconnect stat.
Disconnect fan stat.
When fan temp < 60° C
is there continuity
across stat ?
YES
Reconnect stat.
Disconnect the larger of
the 6-way PCB connectors.
Is there continuity
across M ?
YES
Disconnect
thermistor
(red sensor on flow pipe).
Is resistance between
0.5k & 20k
YES
Is
combustion chamber
door seal damaged or not in
place ?
NO
Replace PCB.
58
© Baxi Heating UK Ltd 2014
Flash Off On
NO
Replace Stat.
NO
Replace Stat.
NO
Wiring from PCB to
thermostats faulty.
NO
Replace thermistor.
?
YES
Replace combustion
chamber door seal & trim
Lights
ON
seal.
17.0 Fault Finding
M
6-way Connector