Navien is a leading brand in the tankless water heater market, providing energy-efficient and
reliable solutions for homes and businesses. However, like any mechanical device, Navien
tankless water heaters can experience errors and malfunctions that require troubleshooting and
repair. In this article, we'll cover the most common Navien tankless water heater error codes and
their meanings, so you can identify and resolve any issues quickly and efficiently.

1. Navien Error Code 001 - This error code indicates an ignition failure, which can be caused
by a gas supply problem, a blocked or dirty air filter, or a damaged ignition device. Check the
gas supply, air filter, and ignition device, and clean or replace them as necessary.

2. Navien Error Code 002 - This error code indicates an overheating problem, which can be
caused by a faulty temperature sensor or a clogged heat exchanger. Check the temperature
sensor and heat exchanger, and clean or replace them as necessary.

3. Navien Error Code 003 - This error code indicates a circulation pump problem, which can be
caused by a faulty pump or wiring connections. Check the pump and wiring connections, and
replace or repair them as necessary.

4. Navien Error Code 004 - This error code indicates a flow sensor problem, which can be
caused by a faulty sensor or wiring connections. Check the sensor and wiring connections, and
replace or repair them as necessary.

5. Navien Error Code 006 - This error code indicates a fan motor problem, which can be
caused by a faulty motor or wiring connections. Check the motor and wiring connections, and
replace or repair them as necessary.

6. Navien Error Code 010 - This error code indicates an exhaust blockage or improper venting,
which can be caused by a clogged vent pipe or flue, insufficient ventilation, or incorrect
installation. Check the venting system and installation, and clean or replace components as
necessary.

7. Navien Error Code 012 - This error code indicates a flame loss, which can be caused by
insufficient gas supply, low gas pressure, or a dirty burner. Check the gas supply and pressure,
and clean the burner as necessary.

8. Navien Error Code 013 - This error code indicates a thermistor problem, which can be
caused by a faulty sensor or wiring connections. Check the thermistor and wiring connections,
and replace or repair them as necessary.

9. Navien Error Code 016 - This error code indicates a communication error between the circuit
board and other components, which can be caused by a faulty circuit board or wiring
connections. Check the circuit board and wiring connections, and replace or repair them as
necessary.

10. Navien Error Code 021 - This error code indicates a problem with the water inlet thermistor,
which can be caused by a faulty sensor or wiring connections. Check the thermistor and wiring
connections, and replace or repair them as necessary.

11. Navien Error Code 022 - This error code indicates a problem with the outgoing water
thermistor, which can be caused by a faulty sensor or wiring connections. Check the thermistor
and wiring connections, and replace or repair them as necessary.

12. Navien Error Code 027 - This error code indicates an overvoltage problem, which can be
caused by a power surge or faulty electrical components. Check the electrical system and
components, and replace or repair them as necessary.

13. Navien Error Code 029 - This error code indicates a problem with the air pressure sensor,
which can be caused by a faulty sensor or wiring connections. Check the sensor and wiring
connections, and replace or repair them as necessary.

14. Navien Error Code 038 - This error code indicates a problem with the combustion chamber
or flame rod, which can be caused by a dirty or damaged flame rod or improper combustion

15. Navien Error Code 040 - This error code indicates a problem with the air intake filter, which
can be caused by a dirty or clogged filter. Check the air intake filter and clean or replace it as
necessary.

16. Navien Error Code 048 - This error code indicates a problem with the mixing valve, which
can be caused by a faulty valve or wiring connections. Check the valve and wiring connections,
and replace or repair them as necessary.

17. Navien Error Code 055 - This error code indicates a problem with the heat exchanger,
which can be caused by a dirty or clogged heat exchanger. Check the heat exchanger and
clean or replace it as necessary.

18. Navien Error Code 057 - This error code indicates a problem with the water pressure
sensor, which can be caused by a faulty sensor or wiring connections. Check the sensor and
wiring connections, and replace or repair them as necessary.

19. Navien Error Code 060 - This error code indicates a problem with the gas valve or
regulator, which can be caused by a faulty valve or regulator or wiring connections. Check the
valve or regulator and wiring connections, and replace or repair them as necessary.

20. Navien Error Code 069 - This error code indicates a problem with the fan or fan motor,
which can be caused by a faulty fan or fan motor or wiring connections. Check the fan or fan
motor and wiring connections, and replace or repair them as necessary.

By understanding these error codes and their meanings, you can troubleshoot and repair your
Navien tankless water heater quickly and effectively. However, it's always best to contact a
professional Water Heater Technician for assistance. With regular maintenance and timely
repairs, your Navien tankless water heater can provide years of reliable, energy-efficient service
for your home or business.

The Water Heater Company is a small family-owned and operated business. If you are in our
service area and need assistance with your tankless water heater, give us a call. We look
forward to helping you with your water heater repair and maintenance needs.