Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove the leads from the gas valve and unplug the large (20 way) ST9 connector from the right hand side of the PCB
Measurement:
Check for continuity across the gas valve harness, at positions 1, 2, 3 & 4 of ST9 to the gas valve connectors.
Check the general lead condition.
Note:
1. Ensure a good, firm contact is made with the gas valve lead connectors.
2. Colours may vary from those shown but the terminals will remain the same.
Check the general lead condition.
Note:
1. Ensure a good, firm contact is made with the gas valve lead connectors.
2. Colours may vary from those shown but the terminals will remain the same.
Isolate as per TOPs P4
and refit as necessary