Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
Turn Hot Water Tap On
Gain access to PCB (use Insulation Mat as required)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Cancel purge cycle & If required, reset boiler.
Measure the AC voltage between pins 1 and 2 on connector CN5.
Expect mains voltage.
Note:
Number 1 is indicated on the PCB with the numbering running right to left.
Measure the AC voltage between pins 1 and 2 on connector CN5.
Expect mains voltage.
Note:
Number 1 is indicated on the PCB with the numbering running right to left.
Isolate as per TOPs P4
and refit as necessary