Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Remove leads to flue thermistor

Measurement:

Measure for resistance across the exposed pins of the flue thermistor.
The resistance depends on temperature and should
conform to the table below:
Flow Temperature °CResistance in kOhms
10 - 2019.0 - 12.0
20 - 3012.0 - 8.0
30 - 408.0 - 5.0
40 - 505.0- 3.8
50 - 603.8 - 2.5
60 - 702.5 - 1.7
70 - 801.7 - 1.3