Set Appliance State:

Gas Off
Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to AC Volts Set meter to measure AC Volts
Gain access to pump wiring
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Allow boiler self check to complete.
Hold down the service mode button for more than 5 seconds to
enable service mode.
Measure the voltage across L and N terminal connections on the pump.
Mains voltage expected.
Note:
Pump is located external to appliance.
Wiring may differ to example shown.