Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect plug marked X6a from the PCB
Determine correct Gas Valve lead Brown and Blue wires on disconnected plug

Measurement:

Check for a resistance reading across the terminals at the disconnected plug
Resistances approx. as follows:
PinsResistance in kOhms
Brown & Blue1.2


Note:
Ensure a good connection is made.