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 pins 1 and 2
on the gas valve.
Resistance should be approximately 1.6kOhms.
Test 2:
Measure the resistance between pins 4 and 5
on the gas valve.
Resistance should be approximately 2.8kOhms.
Test 3:
Measure the resistance between each of the four pins (1, 2, 4 and 5), in turn, to a suitable earth point.
Resistance should be above 1M Ohm on each of the 4 checks.
Measure the resistance between pins 1 and 2
on the gas valve.
Resistance should be approximately 1.6kOhms.
Test 2:
Measure the resistance between pins 4 and 5
on the gas valve.
Resistance should be approximately 2.8kOhms.
Test 3:
Measure the resistance between each of the four pins (1, 2, 4 and 5), in turn, to a suitable earth point.
Resistance should be above 1M Ohm on each of the 4 checks.
Isolate as per TOPs P4
and refit as necessary