Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect the lead from the flame sense electrode
Measurement:
Measure the resistance of the flame sense electrode.
Expect short circuit / zero resistance.
Also visually inspect the electrode for signs of damage,
cracked ceramic insulation, good general condition and
that it is correctly positioned above the burner.
Expect short circuit / zero resistance.
Also visually inspect the electrode for signs of damage,
cracked ceramic insulation, good general condition and
that it is correctly positioned above the burner.
Isolate as per TOPs P4
and refit as necessary