Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to AC Volts Set meter to measure AC Volts
CH Demand
Gain access to PCB (use Insulation Mat as required)
Thermostat to Max position
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Test 1:
Measure Mains Voltage across the pump Live terminal (marked L) and the pump Earth terminal on the pump connector block.
Test 2:
Measure Mains Voltage across the pump Neutral (terminal (marked N) and the pump Earth terminal (Blue) on the pump connector block.