Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Carefully remove the electrode assembly from
the combustion box door

Measurement:

Thoroughly inspect the electrodes as below:
  • Ceramics not cracked.
  • Electrodes not warped or distorted.
  • No build-up of contamination on electrodes.
  • Detection electrode approx. 18mm in length (not burnt down).
  • Spark gap is 3.5mm +/- 0.5mm.
  • Connectors to PCB and rectification harness are a tight fit.
    Measure the resistance between the tip of each electrode and its corresponding wire.
    Expect continuity / zero resistance.
    Note:
    Before reassembly check the integrity of all disturbed gaskets and seals and replace as necessary.