Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect plug from gas valve
Measurement:
Test 1:
Measure the resistance across the pins of the gas valve.
Resistance depends on which gas valve is fitted:
Honeywell valve resistance should be approximately 115 Ohms.
SIT valve resistance should be approximately 70 Ohms.
Test 2:
Measure the resistance between one of the pins on the gas valve and a suitable earth.
Resistance should be greater than 1M Ohm (or O.L on meter).
Are the resistances measured as expected?
Measure the resistance across the pins of the gas valve.
Resistance depends on which gas valve is fitted:
Honeywell valve resistance should be approximately 115 Ohms.
SIT valve resistance should be approximately 70 Ohms.
Test 2:
Measure the resistance between one of the pins on the gas valve and a suitable earth.
Resistance should be greater than 1M Ohm (or O.L on meter).
Are the resistances measured as expected?
Isolate as per TOPs P4
and refit as necessary