Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect plug connector (marked ST16) from PCB
Measurement:
Test 1:
Check resistance across connections 7 & 8 (brown wires)
Test 2:
Check resistance across connections 9 & 10 (violet wires).
Resistance should be approximately 155 Ohms on both tests.
Note:
Care should be taken that probe tips do not touch each other when taking measurement as a false reading will be given. Also ensure that other end of leads are connected to the main gas valve.
Check resistance across connections 7 & 8 (brown wires)
Test 2:
Check resistance across connections 9 & 10 (violet wires).
Resistance should be approximately 155 Ohms on both tests.
Note:
Care should be taken that probe tips do not touch each other when taking measurement as a false reading will be given. Also ensure that other end of leads are connected to the main gas valve.
Isolate as per TOPs P4
and refit as necessary