Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect plug from gas valve
Observation:
Test 1:
Measure the resistance between pin 1 (top) and pin 4 (bottom) at the gas valve.
Resistance should be approximately 7.4kOhms.
Test 2:
Measure the resistance between pin 1 (top) at the gas valve to a suitable earth point.
Resistance should be at least 1M Ohm.
Note:
Pins are numbered on the gas valve.
Measure the resistance between pin 1 (top) and pin 4 (bottom) at the gas valve.
Resistance should be approximately 7.4kOhms.
Test 2:
Measure the resistance between pin 1 (top) at the gas valve to a suitable earth point.
Resistance should be at least 1M Ohm.
Note:
Pins are numbered on the gas valve.
Isolate as per TOPs P4
and refit as necessary