Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Unplug electrode from HT lead
Remove electrode from heat exchanger
Remove electrode from heat exchanger
Observation:
Thoroughly check the electrode and lead for signs of damage, cracked ceramic insulation, continuity and good general condition.
Refit electrode after test.
Also check the electrode is straight and the correct distance from the burner, if in doubt measure the gap as shown. It should be 7-9mm
Refit electrode after test.
Also check the electrode is straight and the correct distance from the burner, if in doubt measure the gap as shown. It should be 7-9mm
Isolate as per TOPs P4
and refit as necessary