Set Appliance State:

Set Multimeter to AC Voltage Set meter to measure AC Volts
CH Demand
Isolate Mains Power to appliance as per TOPs P4
Boiler mains switch On
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Measurement:

Measure voltage across brown lead (live) and pink lead (neutral) at PCB side of inline connector.