Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect lead from gas valve
Measurement:
Test 1:
Measure the resistance between the top and bottom pins of the gas valve.
Resistance should be approximately 42 Ohms.
Test 2:
Measure the resistance between the top pin of the gas valve to a suitable earth point.
Resistance should be greater than 1M Ohm.
Measure the resistance between the top and bottom pins of the gas valve.
Resistance should be approximately 42 Ohms.
Test 2:
Measure the resistance between the top pin of the gas valve to a suitable earth point.
Resistance should be greater than 1M Ohm.
Isolate as per TOPs P4
and refit as necessary