Navien NFC-175, Service Manual

Page: 74 / 138

74 NFC Service Manual
Version 1.0
5.2.2 003Error
Error occurrence conditions and check items
Error Description
E003
Ignition failure
In the case of an ignition failure, the boiler will attempt ignition 10 times. If no flame is
detected, the system displays the error message 003E (manually cleared) on the Front Panel.
Check items
1. Check if the gas supply valve is open and use a manometer to verify proper supply
pressure.
2. Check the electrode gap, electricity discharge, or deformation of the flame rod.
3. Check the operation of the ignition transformer (ignition state, input power (AC 120 V).
4. Check the operation of the gas control valve (DC 22~24 V, coil short circuit, solenoid valve).
5. Check the flame rod, wiring and grounding.
6. Check if the air pressure hose is broken or clogged.
7. Check if the air pressure sensor works properly.
8. Check the PCB DIP switch settings.
9. Adjust the offset pressure (see page 29-30).
10. Check the gas orifice plate for the proper gas type.
11. Check the flue and air supply for any collected water (for vertical vent installations).
12. If the issues continue despite checking the items above, replace the PCB.
Scenario1
Is the igniter operating
normally?
Does the igniter have
proper voltage?
Is the igniter
electrode clean?
Is the igniter electrode
damaged?
Check the gas valve assembly Replace igniter assembly
Clean or replace igniter electrode
Check connector
Check the voltage between #4 and #5 of CNO1:
Same as supply voltage (97 – 138 VAC)
(see page 50-51 for Wiring Diagram)
Yes
No No
No
Yes
Yes