Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Disconnect rectification lead from ignition control box (rear lead)
Measurement:
Test 1:
Measure the rectification electrode gap from the burner.
This should be 8 - 10mm.
Test 2:
Measure the resistance between the tip of the rectification electrode and the lead connector.
Expect continuity / zero resistance.
Test 3:
Visually inspect the condition of the electrode and lead for good general condition (paying particular attention to where the harness passes through the burner and case as this area is prone to shorting).
Is the rectification electrode and lead satisfactory?
Measure the rectification electrode gap from the burner.
This should be 8 - 10mm.
Test 2:
Measure the resistance between the tip of the rectification electrode and the lead connector.
Expect continuity / zero resistance.
Test 3:
Visually inspect the condition of the electrode and lead for good general condition (paying particular attention to where the harness passes through the burner and case as this area is prone to shorting).
Is the rectification electrode and lead satisfactory?
Isolate as per TOPs P4
and refit as necessary