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)
Remove the connector from the fan assembly and make safe
Remove the connector from the fan assembly and make safe
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Allow boiler self-check to complete.
Reset appliance as necessary (hold down both arrow buttons until display changes).
Measure the AC voltage between each of the pins listed below and pin 3 (purple), the voltages measured should be approximately as listed in the table.
Are the voltages measured as expected?
Reset appliance as necessary (hold down both arrow buttons until display changes).
Measure the AC voltage between each of the pins listed below and pin 3 (purple), the voltages measured should be approximately as listed in the table.
| Pin | Voltage |
| 4 (Brown) | 240V AC |
| 5 (White) | 36V AC |
| 6 (Orange) | 36V AC |
| 7 (Yellow) | 36V AC |
Are the voltages measured as expected?
Isolate as per TOPs P4
and refit as necessary