Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
CH Demand
Gain access to PCB (use Insulation Mat as required)
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
Reset boiler as required.
Measure the voltage to earth at the yellow wire of the 6 way plug towards the rear of the PCB. This is the power supply from the PCB to the pump.
Expect mains voltage.
Measure the voltage to earth at the yellow wire of the 6 way plug towards the rear of the PCB. This is the power supply from the PCB to the pump.
Expect mains voltage.
Isolate as per TOPs P4
and refit as necessary