004Error - Navien NPE-180A Service Manual

Failure mode
Check if there are any
Flame loss and noise
blockages in the gas
occurs at ignition
orifice plate.
Improper air intake air
Rainwater intrusion
supply
Screw loosening
Other trouble
Defective PCB

5.1.2 004Error

Error occurrence conditions and check items
Error
1. Pre ignition false-flame
If a flame signal is detected continuously for 3 seconds before combustion (stand-by, pre-purge, pre-
ignition), a false-flame error 04E (automatically cleared) is displayed on the front panel and the system
performs continuous post-purge and operates the pump.
E04
False-flame detection
2. Post purge false-flame
If a flame signal is detected continuously for 3 seconds when the system performs post-purge as fuel supply
is stopped, a false-flame error 004E (automatically cleared) is displayed on the front panel and the system
performs continuous post-purge and operates the pump.
Cause
Ignition failure will occur if the gas orifices are clogged.
Remove the gas inlet pipe and check the orifice plate.
●
Check if rainwater has collected inside the unit from an improperly installed air intake
pipe.
Tighten the ground connection screws on heat exchanger.
If the issue continues despite checking above items, replace the PCB.
Check method
Description
Troubleshooting 81