Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove 8 way connector from water sensor PCB
Measurement:
Measure for resistance across pins 1 & 2 of disconnected 8 way connector.
Although the condensate resistor is not a thermistor it does still have a negative temperature coefficient, as a result when the appliance combustion chamber is warmer the resistance measured will be lower and vice versa.
Expect a resistance between 170 kOhms and 400 kOhms.
The resistance measured should lie between these values relative to the appliance combustion chamber temperature.
Is resistance measured as expected?
Note:
Ensure a good connection is made as misdiagnosis will occur.
Although the condensate resistor is not a thermistor it does still have a negative temperature coefficient, as a result when the appliance combustion chamber is warmer the resistance measured will be lower and vice versa.
Expect a resistance between 170 kOhms and 400 kOhms.
The resistance measured should lie between these values relative to the appliance combustion chamber temperature.
Is resistance measured as expected?
Note:
Ensure a good connection is made as misdiagnosis will occur.
Isolate as per TOPs P4
and refit as necessary