Navien CH-180 Service manual - page 71

69

Error conditions and check items

5.5. 04Error

Error

04E

False-flame 

detection

Check items

Description

1. Pre ignition false-flame

If a flame signal is detected before combustion (standby, prepurge, preignition), 

a false-flame error 04E (automatically cancelled) is displayed on the indoor 

thermostat, and the system performs continuous postpurge.

2. Post purge false-flame

If a flame signal is detected when the system performs post-purge as fuel 

supply is stopped, a false-flame error 04E (automatically cancelled) is 

displayed on the indoor thermostat, and the system performs continuous 

postpurge.

1. Check if gas leaks due to defective sealing of the main gas valve.

2. Check if electricity is discharged from the electrode.

3. Check if gas is supplied at higher pressure than the standard gas pressure.

4. Defective PCB.

Is the flame detected

during no burner

operation?

Yes

No

Check the current of CN 19: 7 - 20μA

Check the voltage between two wires

of CN 19: 10-20VDC 

Replace PCB

Clean or replace flame rod

©Navien America Inc. 2010

CH  series service Manual

Version 1.0