Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
NO Demands
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
Measure the AC voltage between the Brown and Blue wires at the 3 wire fan connector on the fan assembly.
Expect mains voltage.
Expect mains voltage.
 gas setup and fan.gif)
 ac fan connector.gif)
Isolate as per TOPs P4
and refit as necessary