Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Voltage 
Turn Hot Water Tap On
Gas On; Pilot On
Boiler On/Off Switch ON
CH Switch OFF
DHW Switch in INSTANT position
Remove pump wiring cover
Boiler On/Off Switch ON
CH Switch OFF
DHW Switch in INSTANT position
Remove pump wiring cover
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
Measure the voltage across terminal L (brown wire) and the terminal N (blue wire) at the pump.
Isolate as per TOPs P4
and refit as necessary