Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to DC Volts 
Gain access to PCB (use Insulation Mat as required)
| WARNING! - Mains voltage is expected during test follow TOPs P4 live testing procedure |
Measurement:
Measure the DC voltage between each of the pins on connector X51 and an earth (use the copper pipe to the gas valve as earth).
Expected voltages are as per the table below:
Are the voltages measured as expected?
Expected voltages are as per the table below:
| Pin | DC Volts | 1 | 4.8 |
| 2 | 22.5 |
| 3 | 4.9 |
| 4 | 21.7 |
| 5 | 4.9 |
| 6 | 0 |
Are the voltages measured as expected?
Isolate as per TOPs P4
and refit as necessary