Potterton Promax System HE Plus LPG Installation & Service Instructions Manual page 51

E
Temperature sensors faulty.
Cold resistance approximately
10kΩ @ 25° C (DHW and CH sensors)
20kΩ @ 25° C (Flue sensor)
(resistance reduces with increase in temp.)
F
1.
Check and correct the connection of the
tube between the venturi and gas valve
2. Gas at burner
G
Check and correct if necessary
1. Ignition electrode and lead
2. Electrode connection
3. Spark gap and position
© Baxi Heating UK Ltd 2008
NO
NO
Ensure gas is on and purged
PCB - X3 connector is 230V AC across
terminals 1 & 2
NO
Replace PCB
Voltage at PCB - X2 connector is at
least 100V DC across terminals 2 & 5
YES
(Note: from multimeter connect
'common' to 2 & 'volt' to 5)
Check wiring
Burner
7.5 ± 1
Electrode Position
18.0 Fault Finding
Replace sensor
YES
Replace gas valve
NO
YES
Viewing Window
4 ± 0.5
10 ± 1
Replace PCB
Replace igniter
51