Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to AC Volts 
CH Demand
Gain access to PCB (use Insulation Mat as required)
Remove electrical connector from diverter valve and make safe
Turn DHW temperature control to MIN (ensures no preheat)
Remove electrical connector from diverter valve and make safe
Turn DHW temperature control to MIN (ensures no preheat)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Boiler On/Off Switch On.
Allow fan to run and burner to ignite.
Measure the AC voltage between the two right hand purple wires of the diverter valve connector, terminals 2 and 3.
Expect approximately 30 VAC.
Note:
It can be difficult to test in the top of the connector, access to test can also be gained though the small holes on the underside of the connector as highlighted on the right.
Allow fan to run and burner to ignite.
Measure the AC voltage between the two right hand purple wires of the diverter valve connector, terminals 2 and 3.
Expect approximately 30 VAC.
Note:
It can be difficult to test in the top of the connector, access to test can also be gained though the small holes on the underside of the connector as highlighted on the right.
Isolate as per TOPs P4
and refit as necessary