Set Appliance State:
Mains Reset Switch OFF
Set Multimeter to AC Volts 
Isolate Mains Power to appliance as per TOPs P4
Ensure the boiler is cool so that there is demand for preheat
Set DHW temperature selector to ECO
Set CH temperature selector to OFF
Remove control panel rear cover to expose main PCB
Ensure the boiler is cool so that there is demand for preheat
Set DHW temperature selector to ECO
Set CH temperature selector to OFF
Remove control panel rear cover to expose main PCB
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Mains reset switch On.
Measure voltage across terminal 3 (black wire) and terminal 2 (brown wire) at connector marked H5 on the main PCB.
Mains voltage expected.
Measure voltage across terminal 3 (black wire) and terminal 2 (brown wire) at connector marked H5 on the main PCB.
Mains voltage expected.
Isolate as per TOPs P4
and refit as necessary