Set Appliance State:
Set Multimeter to AC Volts 
DHW Demand
| WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure |
Measurement:
NOTE: The pump is not an integral part of the boiler it will be located elsewhere on the system.
Remove the connection cover from the pump and with the external controls calling for heat check for voltage across the terminals marked L and N of the pump.
Expect mains voltage.
Remove the connection cover from the pump and with the external controls calling for heat check for voltage across the terminals marked L and N of the pump.
Expect mains voltage.
Isolate as per TOPs P4
and refit as necessary