Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
DHW Demand
Ensure there is a demand for DHW i.e. hot water cylinder is cold
Set temperature selector to MAX
Gain access to PCB (use insulation mat as necessary)
Mains reset switch On
Set temperature selector to MAX
Gain access to PCB (use insulation mat as necessary)
Mains reset switch On
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure voltage across the live (brown lead) and neutral (blue lead) connection on the connector marked H1 on the main PCB.
Isolate as per TOPs P4
and refit as necessary