Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to AC Volts Set meter to measure AC Volts
Turn Hot Water Tap On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Boiler On/Off switch On.
Reset lockout if necessary.
Measure voltage at the brown lead (live) and the blue lead (neutral) at the pump connector marked ST11 on the PCB.
Note:
Ensure good probe connection to test points.