Navien NFC-175, Service Manual

Page: 68 / 138

68 NFC Service Manual
Version 1.0
5.2 Error code classification
Error Code Sub Code Function / Cause Self-diagnostic / Action
E001
1
Overheating of Heat exchanger
1. Clean the strainer.
2. Check the pump for proper voltage from
PCB(120VAC).
3. Check for proper flow rate and
circulation(external) through the heating line.
4. Check the heat exchanger ; flush with a cleaning
solution.
2
E003 0 Ignition failure
1. Check to see if the main gas supply valve is open.
2. Verify that gas pressure is within operating
range.
3. Check gas system and orifice.
4. Check Dual Venturi for restrictions in the gas
ports.
5. Check for proper DIP switch settings (see
page 20).
6. Verify proper grounding and ground wire
connections to PCB lower bracket.
E004 0 False flame detection
1. Ensure ground wire is connected.
2. Check the igniter for spark.
E012 0 Flame loss
1. Check the main gas line. (Is the valve open?)
2. Verify gas pressure is within operating range.
3. Check gas meter for proper BTU capacity.
4. Check flame rod and verify #14 value in the
Status Information menu (see page 36).
5. Check intake air filter.
6. Check ground wire.
7. Check power supply.
8. Verify proper grounding and ground wire
connections to PCB lower bracket.
9. Adjust anti-fast cycle time referring to #11 value
in the Operation Parameters (see page 43).
E016 0 Overheating of heat exchanger
1. Turn OFF the system for at least 30 minutes then
restart.
2. Ensure all valves and filters on the boiler loop are
open and clean.
3. Check for proper DIP switch settings (see
page 19-20) and PCB.
4. Check the heat exchanger; a flush may be
necessary.
5. Verify that all air elimination devices are
operational. Perform a manual air purge the
heating piping.