Technical data

46
© Baxi Heating UK Ltd 2012
17.0 Fault Finding
I
Temperature sensors faulty.
Cold resistance approximately
10kΩ @ 25° C (CH sensor)
20kΩ @ 25° C (Flue sensor)
(resistance reduces with increase in temp.)
NO
Replace sensor
YES
If pump is running the heat exchanger could be
obstructed
Replace heat exchanger
1.
2.
Replace hydraulic pressure sensor
YES
Restore system pressure
YES
NO
CH system pressure less than
0.5 bar or greater than 2.7 bar
Check wiring and PCB - X22
connector for approx. 5V DC
between green & black - see
Wiring Diagram
Replace PCB
NO
J
Replace sensor
NO
System fault - correct
NO
YES
Ensure that the boiler and system
are fully vented
Check flow temperature sensor connections
and position.
Cold resistance approximately
10kΩ @ 25° C (CH sensors)
(resistance reduces with increase in temp.)
YES
Go to section ‘B’
K