Set Appliance State:
| Isolate Mains Power to appliance as per TOPs P4 |
Set Multimeter to Resistance 
Remove flame detection electrode from its housing
Unplug connection from PCB
Unplug connection from PCB
Measurement:
Test 1:
Carry out a continuity check of the earth lead between the PCB connector and the fan earth tab.
Expect zero resistance.
Test 2:
Carry out a continuity check of the flame sense lead between the PCB connector and detection electrode connection.
Expect zero resistance.
Test 3:
Thoroughly inspect the condition of the earth and rectification leads, looking for damaged insulation, evidence of the lead being trapped or heat damaged and excessively tight bends or kinks.
Carry out a continuity check of the earth lead between the PCB connector and the fan earth tab.
Expect zero resistance.
Test 2:
Carry out a continuity check of the flame sense lead between the PCB connector and detection electrode connection.
Expect zero resistance.
Test 3:
Thoroughly inspect the condition of the earth and rectification leads, looking for damaged insulation, evidence of the lead being trapped or heat damaged and excessively tight bends or kinks.
Isolate as per TOPs P4
and refit as necessary