Set Appliance State:
On/Off Switch OFF
Set Multimeter to AC Volts 
DHW Demand - Ensure Store is not up to Temperature
Isolate Mains Power to appliance as per TOPs P4
DHW temperature selector to maximum position
Gain access to PCB connections as necessary
DHW temperature selector to maximum position
Gain access to PCB connections as necessary
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Appliance On/Off switch On.
Reset lockout as necessary.
Measure voltage across connection 1 (brown wire) and connection 3 (blue wire) at connector J7 at the PCB.
Reset lockout as necessary.
Measure voltage across connection 1 (brown wire) and connection 3 (blue wire) at connector J7 at the PCB.
Isolate as per TOPs P4
and refit as necessary