Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
Gain access to PCB (use Insulation Mat as required)
Selector switch to OFF position
CH temperature selector to minimum
DHW Preheat selector to OFF position
Selector switch to OFF position
CH temperature selector to minimum
DHW Preheat selector to OFF position
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure voltage between pins 5 and 7 at connector A2 on the PCB.
Is mains voltage present?
Is mains voltage present?
Isolate as per TOPs P4
and refit as necessary