Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect plug for thermal fuse / flue thermistor
Measurement:
Measure the resistance across the thermal fuse component of the combined thermistor / fuse.
Resistance should be short circuit (zero resistance).
Note:
Thermal fuse / thermistor is factory fitted with the catch at the top but can also be rotated by 180°, refer to pictures and ensure test is done against correct pins.
Resistance should be short circuit (zero resistance).
Note:
Thermal fuse / thermistor is factory fitted with the catch at the top but can also be rotated by 180°, refer to pictures and ensure test is done against correct pins.
Isolate as per TOPs P4
and refit as necessary