Navien NCB-150E Service Manual page 93

Failure mode
Ignition failure
92 NCB-E Service Manual
Cause
Bracket
Igniter
Flame Red
Ignite gap distance : 3.5-4.5mm (1/8")
When no spark is made from the electrode at ignition:
Remove the electrode and check if there is a crack on the insulator.
●
Adjust the gap if there is a discharge of electricity from the metallic part of the
●
burner.
Ensure that the insulating gasket is installed between the electrode and burner
●
casing.
No spark from
electrode
Check the input power to the ignition transformer (AC 96 - 138 V).
●
If there is sufficient power to the ignition transformer, replace the ignition
●
transformer.
Replace the PCB if there is no power or insufficient power supplied to the ignition
●
transformer.
Check the insulator boots on the spark wires for cracks/holes.
●
Check method
Ignition transformer
Version 1.4