Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove the ignition control box from the gas valve
Measurement:
Test 1:
Measure the resistance across terminal marked EV1 (bottom)
and terminal marked COM (right).
Resistance should be approximately 870 ohms.
Test 2:
Measure the resistance across terminal marked EV2 (top)
and terminal marked COM (right).
Resistance should be approximately 870 ohms.
Test 3:
Measure the resistance across terminal marked COM (right)
and gas valve earth (left).
Resistance should be greater than 1Mohm.
(O.L is acceptable because this is greater than 1Mohm)
Are the resistances measured as expected?
Measure the resistance across terminal marked EV1 (bottom)
and terminal marked COM (right).
Resistance should be approximately 870 ohms.
Test 2:
Measure the resistance across terminal marked EV2 (top)
and terminal marked COM (right).
Resistance should be approximately 870 ohms.
Test 3:
Measure the resistance across terminal marked COM (right)
and gas valve earth (left).
Resistance should be greater than 1Mohm.
(O.L is acceptable because this is greater than 1Mohm)
Are the resistances measured as expected?
Isolate as per TOPs P4
and refit as necessary