Set Appliance State:

Mains Power Off
Set Multimeter to Resistance Set meter to measure resistance
Isolate Mains Power to appliance as per TOPs P4
Ensure that the Appliance is switched OFF.
Room Thermostat calling for heat (if fitted).

Measurement:

Measure a short circuit resistance across the Room Thermostat Connections 9 and 10 (on the 12 way Terminal Block).
Note:
If no Room Thermostat is installed, a factory fitted link, will be in place between connections 9 and 10.
If a Room Thermostat is fitted the link MUST be removed.