Navien Error Codes
Tankless Systems are complicated systems that can have some errors and electronic issues. We have put together a thorough list of Navien error codes to help you diagnose and potentially fix any issues you may have.
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| Code | Error | Troubleshoot | Solution | Replacement Parts |
|---|---|---|---|---|
| E001 | Water is boiling in the Heat Exchanger | 1. clean the inlet water strainer. 2. Check the automatic flow sensor. 3. Check the heat exchanger, remove and clean with a solution 4. Check PCB board, replace if faulty. | Solution Details 001E OR power Supply | 1. Inlet Water Filter 2. Water Adjustment Valve NPE-A 3. Water Adjustment Valve 30004834B 4. Navien Flush Kit 5.Navien CB 30000181A 6.Navien CB 30012262A 7.Navien CB 30008300A |
| E002 | Low Water Pressure | 1.Wait until water supplement is terminated. | Reset Is Automatic | None Needed |
| E003 | Ignition Failure | 1. Check to see if the main gas supply is on 2. Check that the power is on 3. Check the igniter for spark | Scenario 1 Scenario 2 Scenario 3 | 1.Flame Rod NPE/NCB 2.Flame Rod CR/CC/CH/NR/NP 3.Flame Rod CR/CC/CH/NR/NP 4.Flame Rod NPE/NCB |
| E004 | False flame detection | 1. Ensure ground wire is connected 2. Check the igniter for spark | Solution Details 004E | Flame Rod Assembly |
| E007 | Hot water outlet: thermistor -open | 1. Check the thermistor 2. Replace the thermistor | Solution Details 007E | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E008 | Hot water outlet: thermistor -short | 1. Check the thermistor 2. Replace the thermistor | Solution Details 008E | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E009 | Abnormal fan motor activity | 1. Check and clean the air filter 2. Check and clean the fan motor 3. If faulty, replace fan. | Solution Details 009E | 1. Navien Fan 30008834A 2. Navien Fan 30000405A |
| E010 | Abnormal Air Pressure | 1. Check the vent pipe for obstructions 2. Check and clean the air filter | Solution Details 010E | None Needed |
| E011 | High Water Pressure | 1. Check the water pressure sensor. | Automatic Reset or replace sensor. | Water Pressure Sensor |
| E012 | Flame loss | 1. Check the main gas line (valve open?) 2. Check intake air pipe 3. Check the ground wire 4. Check power supply | Solution Details 012E | Navien Ignition Transformer |
| E015 | Abnormal control board | 1. Check power supply 2. Check the GFI | Not Defined | 1. Navien CB 30000181A 2. Navien CB 30012262A 3. Navien CB 30008300A |
| E016 | Overheating of heat exchanger | 1. Turn off the system for at least 30 minutes then restart. 2. Clean the inlet water strainer 3. Check the automatic flow adjustment valve 4. Check the heat exchanger: remove and clean with a cleaning solution | Solution Details 016E | 1. Inlet Water Filter 2. Water Adjustment Valve NPE-A 3. Water Adjustment Valve 30004834B 4. Navien Flush Kit |
| E021 | Cold water inlet: thermistor 1 -open | 1. Check thermistor 2. Replace thermistor | Solution Details 021E | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E022 | Cold water inlet: thermistor 1 -short | 1. Check thermistor 2. Replace thermistor | Solution Details 022E | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E027 | Abnormal activity of the air pressure sensor | 1. Check the vent pipe for obstructions 2. Check and clean the air filter 3. Replace Sensor | Solution Details 027E | Navien Air Pressure Sensor |
| E028 | Water leak pipe line | 1. Check pipe line. 2. Replace O ring | Reset – Manual | 1. Navien O-Ring Kit 2. Navien O-Ring P18 3. Navien O-Ring P16 |
| E030 | Exhaust overheat: exhaust high limit switch shuts down the unit when the flue temperature exceeds 149 F or 65C | 1. Turn off the unit for at least 30 minutes then restart. 2. Clean the inlet water strainer 3. Check the automatic flow adjustment valve 4. Check the heat exchanger: remove and clean with a cleaning solution | Solution Details 030E | 1. Inlet Water Filter 2. Water Adjustment Valve NPE-A 3. Water Adjustment Valve 30004834B 4. Navien Flush Kit |
| E032 | Cold water inlet: thermistor 2 -open | 1. Check thermistor 2. Replace thermistor | Solution Details 032E | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E033 | Cold water inlet: thermistor 2 -short | 1. Check thermistor 2. Replace thermistor | Solution Details 033E | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E034 | Abnormal – flow adjustment valve | 1. Check the flow adjustment valve | Not Defined | Water Adjustment Valve 1. Part 30004834B 2. Part 30008245A |
| E035 | Abnormal activity of the gas pressure sensor | 1. Check gas line | Solution Details 035E | Gas Pressure Flow Sensor |
| E036 | Communication failure | 1. Contact Navien tech support | Not Defined | None Needed |
| E037 | Water leak inside unit | 1. Close cold water main 2. Replace leaking part/O-Ring | Solution Details 037E | 1. Navien O-Ring Kit 2. Navien O-Ring P18 3. Navien O-Ring P16 |
| E038 | Abnormal circulation pump | 1. Check the circulation pump. 2. Check the water flow sensor 3. Check the cold water main | Not Defined | Navien Circulation Pumps. 1. 30012768A 2. 30000466A 3. 30010780B 4. 30000456B |
| E039 | Abnormal – water flow sensor | 1. Check the water flow sensor 2. Replace water flow sensor | Not Defined | Navien flow sensor |
| E041 | Hot water outlet: thermistor 2 -open | 1. Check thermistor 2. Replace thermistor | Not Defined | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E042 | Hot water outlet: thermistor 2 -short | 1. Check thermistor 2. Replace thermistor | Not Defined | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E043 | Abnormal cascade connection | 1. Check model type 2. Check communication cable | Not Defined | Multi-Unit Communication Cable |
| E044 | Abnormal thermistor connection | 1. Check thermistor connection 2.Replace thermistor | Not Defined | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E045 | Abnormal – mixing valve | 1. Check the mixing valve 2.Replace Mixing Valve 3.Check mixing valve transformer | Not Defined | 1. Mixing Valve Transformer 2. Mixing Valve |
| E046 | Abnormality in limit control | Not Defined | Call technical support (800-519-8794) | High Limit Switch |
| E047 | Abnormality in exhaust thermostat | Not Defined | Call technical support (800-519-8794) | Not Applicable |
| E048 | Abnormal LPG gas pressure | 1. Check the LPG gas 2. Fill the LPG gas 3. Check gas pressure flow sensor | Not Defined | Gas Pressure Flow Sensor |
| E060 | Abnormality in dual venturi | 1. Reboot System 2. Replace dual venturi | Call technical support (800-519-8794) | 1. Dual Venturi – 30012770A 2. Dual Venturi – 30008909A |
| E109 | Abnormal operation: fan motor | Clean the intake air filter. | 1. Clean the intake air filter. 2. Reboot system 3. Replace Fan Motor | 1. Navien Fan 30008834A 2. Navien Fan 30000405A |
| E110 | Abnormal air pressure | Not Defined | 1. Ensure that the exhaust pipe is free of obstructions. 2. Clean the intake air filter. 3. Check or replace air pressure sensor | Navien Air Pressure Sensor |
| E407 | Hot water outlet: thermistor open or short circuit | Not Defined | Call technical support (800-519-8794) | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E421 | Cold water inlet1: thermistor open or short circuit | Not Defined | Call technical support | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E432 | Cold water inlet2: thermistor open or short circuit | Not Defined | Call technical support (800-519-8794) | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E434 | Abnormal operation: water adjustment valve | 1. Check adjustment valve. 2. Replace valve | Call technical support | Water Adjustment Valve 1. Part# 30004834B 2. Part# 30008245A |
| E438 | Abnormal operation: circulation pump | Not Defined | 1. External: Ensure that all water supply and return lines are open. 2. Internal: Check the direction of the 2-way valve. | Navien Circulation Pumps. 1. Part# 30012768A 2. Part# 30000466A 3. Part# 30010780B 4. Part# 30000456B |
| E439 | Abnormal operation: flow sensor | Not Defined | Call technical support (800-519-8794) | Gas Pressure Flow Sensor |
| E441 | Hot water inlet2: thermistor open or short circuit | Not Defined | Call technical support (800-519-8794) | Navien Thermistor 1. Blue wire Thermistor 2. Red wire Thermistor 3. Black wire Thermistor |
| E445 | Abnormal operation: Bypass mixing valve | Not Defined | Call technical support (800-519-8794) | 1. Mixing Valve Transformer 2. Mixing Valve |
| E515 | Abnormal operation: PCB | Try new outlet | Ensure that the electrical cord is properly grounded. | 1. Part# 30008300A 2. Part# 30012262A |
| E517 | Abnormal operation: DIP switch setting | Not Defined | Call technical support (800-519-8794) | Not Applicable |
| E593 | Abnormal operation: front panel key | Not Defined | Call technical support (800-519-8794) | Front Panel Kdc-350P |
| E615 | Abnormal operation: input and memory | Not Defined | Call technical support (800-519-8794) | Not Applicable |
| E736 | Abnormal operation: cascade communication | Not Defined | Call technical support (800-519-8794) | Multi-Unit Communication Cable |
| E760 | Flushing/service alarm | Not Defined | Call for flush service (647-925-1930), your installer, or purchase flush kit below. | Navien Flush Kit |
| E782 | Abnormal operation: main panel communication | Not Defined | Call technical support (800-519-8794) | Not Applicable |
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