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Navien boilers are equipped with advanced diagnostic systems that monitor various components and functions. When something goes wrong, the boiler’s control panel displays an error code, providing valuable information to homeowners and technicians. Understanding these error codes can help users diagnose and resolve problems quickly, ensuring the efficient operation of the boiler and preventing further damage.
In this blog post, we will delve into the world of Navien boiler error codes, decoding their meanings, and discussing potential solutions.
Navien Boiler Error Codes
Navien boilers produce oil and gas eco-friendly boilers. They are based in Korea. On this page you will find the error codes and fault codes which are related to Navien boilers. This can help you identify the problem you are having with your Navien boiler.
First, let’s take a look at the history of Navien boilers. The company was founded as Kyungdong Machinery Co. Ltd in 1978. Their first boiler was released in 1979. It is worth mentioning that in 1988 they were the first company in Asia to release a turbo condensing gas boiler.

Their company name was changed in 1991 to Kyungdong Boiler Co. Ltd. After that they launched their Symphony and Harmony ranges of boilers which are wall mounted.
Later on in 2002 they started exporting gas boilers to the United States. What is more, in 2006 they set up Navien America Inc. In 2014, they established Navien UK Ltd.
Although Navien has been in business for more than 40, they haven’t been part of the UK boiler market until recently. However, during these 40 years, they have received many awards in Korea and globally as well.
Navien fault codes are basically the same across all their boilers, which makes it easier to identify what is wrong with your boiler.
Read about: Common Sime Boiler Error Codes
ATAG Boiler Error Codes / Fault Codes
Common Sime Boiler Error Codes
What are Navien error / fault codes?
Boiler System | Error / Fault Code | Fault Description |
Combi and System | 003 | Ignition failure – manual reset needed |
Combi and System | 004 | False flame error – the boiler will auto-reset |
Combi and System | 012 | Flame loss – reset the boiler |
Combi and System | 016 | Heat exchanger overheated – try manually resetting the boiler |
Combi and System | 030 | Abnormal exhaust temperature – try manually resetting the boiler |
Combi and System | 046 | Abnormal operation: Heat exchanger overheating – the boiler should auto-reset |
Combi and System | 047 | Abnormal operation: Exhaust thermostat error – a manual reset is needed if it the boiler doesn’t auto-reset |
Combi and System | 060 | Abnormal operation: Dual venturi limit switch – boiler will auto-reset |
Combi and System | 109 | Abnormal operation: Fan error – the boiler needs resetting |
Combi and System | 110 | Exhaust blockage (condensate blockage) – reset the boiler |
Combi and System | 127 | Abnormal operation: Air pressure switch (APS) issue – reset the boiler |
Combi and System | 205 | Heating supply thermistor open or short circuit – boiler should auto-reset |
Combi and System | 218 | Alarm error: Heating return thermistor open or short circuit |
Combi and System | 302 | Low water pressure – boiler should auto-reset |
Combi and System | 352 | High water pressure – boiler should auto-reset |
Combi and System | 353 | Abnormal operation: Water pressure sensor error – boiler should auto-reset |
System | 407 | Abnormal operation: Hot water outlet thermistor – alarm error |
System | 421 | Abnormal operation: Cold water inlet thermistor Auto reset should automatically occur |
Combi and System | 480 | Abnormal operation: External domestic hot water (DHW) tank outlet thermistor – alarm error |
Combi and System | 515 | Abnormal operation: Relay feedback (PCB) – the boiler needs to be reset |
Combi and System | 517 | Abnormal operation: Dual in-line package (DIP) switch setting (PCB) – boiler needs to be reset |
Combi and System | 594 | Abnormal operation: EEPROM (PCB) – contact an engineer |
Combi and System | 615 | Abnormal operation: Input and memory (MCU) – try resetting the boiler |
Combi and System | 740 | Abnormal operation: Outdoor temperature sensor – boiler should automatically reset |
Combi and System | 782 | Abnormal operation: Main panel communication – boiler should auto-reset |
Read more:
Boiler Replacement And Installation Guide
Glow-Worm Boiler Error Codes / Fault Codes
FAQs
Are Navien boilers reliable?
Navien’s high-efficiency condensing and combi boilers have great value for the price. They’re efficient, affordable, and reliable, but they also have some great new technologies that make controlling your heating system and customizing your home comfort a breeze.
How do I manually reset my Navien boiler?
To reset the boiler, press the Reset button on the front panel. If resetting the boiler and attempting the remedies suggested below do not resolve the problem, contact Navien Technical Assistance Service (TAS) or a Gas Safe Registered Engineer. No water comes out when the hot water tap is opened.
What temperature should a navien boiler be set at?
This Navien Combination boiler is factory set at 120°F (49°C) for your safety and comfort. Increasing the set temperature increases the risk of accidental scalding.