Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC 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:
Reset appliance as necessary.
Allow burner to ignite and establish.
Measure the voltage between Pin 6 (brown) and Pin 7 (blue) on connector X6b. Approx. 210V DC will be present.
Turn Hot Water Tap OFF
(using DHW isolation valve if necessary)
Does the voltage remain after demand ends?
Note:
If a white board is fitted connector is in same location but is called X6 instead of X6b.
Allow burner to ignite and establish.
Measure the voltage between Pin 6 (brown) and Pin 7 (blue) on connector X6b. Approx. 210V DC will be present.
Turn Hot Water Tap OFF
(using DHW isolation valve if necessary)
Does the voltage remain after demand ends?
Note:
If a white board is fitted connector is in same location but is called X6 instead of X6b.
Isolate as per TOPs P4
and refit as necessary