Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Set Multimeter to Resistance Set meter to measure resistance
Disconnect the leads from the electrodes and carefully remove them 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.
    Measure the resistance across each of the 3 electrodes.
    Expect continuity / zero resistance.
    Note:
    Before reassembly check the integrity of all disturbed gaskets and seals and replace as necessary.