Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect 4 pin connector X6 marked "Div Valve" on main driver board

Measurement:

Test 1:
Measure the resistance between the left (nearest to earth wire)
blue and brown wires at CN3.
Resistance will vary by gas valve but should be approximately 1 - 7kOhms.
Test 2:
Measure the resistance between the right blue and brown wires at CN3.
Resistance will vary by gas valve but should be approximately 1 - 7kOhms.
Test 3:
Measure the resistance between the brown
and green/yellow (earth) wires at connector X6.
Resistance should be greater than 1M Ohm.