Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
CH Demand
Selector switch to Heating and Hot Water
Gain access to PCB (use insulation mat as necessary)
Gain access to PCB (use insulation mat as necessary)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Allow fan to start.
Measure voltage across the brown (1) and blue (2) leads on connector X3 on the PCB.
After approximately 5 seconds mains voltage should be present (240 VAC).
Voltage will only be present for approximately 4 seconds.
Measure voltage across the brown (1) and blue (2) leads on connector X3 on the PCB.
After approximately 5 seconds mains voltage should be present (240 VAC).
Voltage will only be present for approximately 4 seconds.
Isolate as per TOPs P4
and refit as necessary