Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect plug from gas valve
(loosen screw holding spark generator)
(loosen screw holding spark generator)
Measurement:
Measure the resistance between the top and bottom pins at the gas valve.
Resistance should be approximately 3.8kOhms.
Resistance should be approximately 3.8kOhms.
Isolate as per TOPs P4
and refit as necessary