Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Remove the yellow leads from DHW thermistor sensor
Ensure DHW is cool (this can be achieved by running the
DHW with the gas to the appliance turned off)
Ensure DHW is cool (this can be achieved by running the
DHW with the gas to the appliance turned off)
Measurement:
Measure resistance across the exposed terminals of the sensor.

Isolate as per TOPs P4
and refit as necessary