Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Disconnect plug (red leads) from primary sensor (senor is shown removed for illustration only)
Note:
Ensure the sensor is correctly attached to the pipe
Note:
Ensure the sensor is correctly attached to the pipe
Measurement:
Measure the Resistance across the two sensor terminals.

Isolate as per TOPs P4
and refit as necessary