Set Appliance State:
Set Multimeter to AC Volts 
Isolate Mains Power to appliance as per TOPs P4
Ensure Room thermostat is calling for heat.
Gain access to PCB (use insulation mat as required)
Ensure Room thermostat is calling for heat.
Gain access to PCB (use insulation mat as required)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Is there Mains voltage across connector X4 connection 2 (L) and connector X7 connection 2 (N)?
Note:
If there is no Room Thermostat ensure connections 1 and 2 are linked together on connector X4.
Note:
If there is no Room Thermostat ensure connections 1 and 2 are linked together on connector X4.
Isolate as per TOPs P4
and refit as necessary