003Error - Navien NFC-175 Service Manual

5.2.2 003Error

Error occurrence conditions and check items
Error
E003
Ignition failure
Check items
Scenario1
Is the igniter operating
normally?
Yes
Check the gas valve assembly
74 NFC Service Manual
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.
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.
No
Does the igniter have
proper voltage?
Yes
Is the igniter
electrode clean?
Is the igniter electrode
damaged?
Yes
Replace igniter assembly
Description
No
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)
No
Clean or replace igniter electrode
Version 1.0