Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect lead from gas valve main solenoid
Measurement:
Test 1:
Measure the resistance across the two outer pins of the gas valve main solenoid.
Resistance should be approximately 4.1kΩ.
Test 2:
Measure the resistance across the top pin of the gas valve solenoid to a suitable earth point.
Resistance should be greater than 1MΩ (or O.L)
Measure the resistance across the two outer pins of the gas valve main solenoid.
Resistance should be approximately 4.1kΩ.
Test 2:
Measure the resistance across the top pin of the gas valve solenoid to a suitable earth point.
Resistance should be greater than 1MΩ (or O.L)
Isolate as per TOPs P4
and refit as necessary