Navien gas boiler errors: deciphering the failure code and ways to solve problems

A gas boiler room in a country house means comfort, warmth, always hot water and saving the family budget on fuel costs.The main thing is that during the cold season the “heart” of the heating system – the gas boiler – does not fail.

Navien brand units have proven themselves to be powerful, reliable machines, easy to install and easy to operate, capable of operating for a long time without repairs or replacement of spare parts. But even with such reliable helpers, sometimes troubles occur - breakdowns due to wear of parts, improper operation or poor quality of the coolant.

Thanks to self-diagnosis, errors in the Navien gas boiler are immediately displayed, and it becomes clear to homeowners which part of the boiler requires attention. We present an overview of the problems that users of Navien boilers most often encounter, as well as tips on how to respond to certain error codes.

Classification of Navien boilers

Gas units of the South Korean brand differ in their installation location and operating principle; accordingly, the error codes stated by the manufacturer in the instructions also differ and may change as new models appear on the market. Let's consider current offers.

Gas-powered models come in two types: wall-mounted and floor-mounted. Wall-mounted units, in turn, are divided into two categories: traditional and condensing.

Traditional series:

• DELUXE;
• DELUXE S;
• DELUXE Comfort;
• ACE (atmo);
• DELUXE PLUS;
• SMART TOK.

Condensation Series:

• NCB 700;
• NFB-98H;
• NPE;
• NCB 52-H.

Currently, only 2 series of floor-standing boilers are produced:

• GA;
• GST.

All models from this manufacturer have a whole list of advantages that have made the brand popular in Russia. According to surveys of users who have been using the technology for a long time, 4 main advantages can be identified:

The assortment is constantly changing: old models are being replaced by updated, more advanced ones. Not long ago, the SMART TOK wall-mounted boiler appeared, which can be controlled directly from a smartphone. The “smart” series has 6 options with power from 13 to 35 kW, and you can choose a comfortable mode right on the way home from work.

Error code instruction

By introducing electronic circuits into the gas boiler control algorithm, manufacturers have made it easier for ordinary users to use the units at home.

Nowadays there is no need to call representatives of the service organization with which contract signed for the supply of fuel, inspection and repair of equipment. Errors are displayed on the electronic display in the form of digital symbols, and instructions for correcting them are given in the technical manual.

Sample control panel. In modern electronic models, the display is located on the control panel, and the symbols are clearly visible even in the dark thanks to the bright LED backlighting in red, orange or blue.

Please note: for Navien boilers, information can be displayed in both digital and alphanumeric characters. This means that there is no difference between error “15” and “E15” - it carries the same information. So, let's move on to the symbols, their decoding and instructions for further actions.

02 – violation of coolant circulation

Outwardly, it looks like this: the heating circuit is operating normally, and cold water suddenly starts flowing from the hot water tap. The information screen, however, displays information about heating the water to the desired temperature.

Reasons for error 02:

• circulation pump failure;
• airing one of the circuits;
• the pressure sensor has failed;
• reduction in pressure below working pressure;
• the tap in the coolant distribution area is closed;
• The automation board is broken.

The consequence of any of the above troubles is the lack of hot circulation coolant.

As you can see, there are many reasons, and each one will have to be considered. We recommend starting with the simplest actions: check if the tap on the manifold is closed, try to bleed air from the system, and equalize the pressure in the network. Check the filters too - circulation may stop due to a simple blockage. In winter, it is quite possible for the pipeline to freeze in an uninsulated section.

If you have a boiler with a closed combustion chamber, code 02 may also appear if the liquid level in the system is insufficient. To eliminate the error, just add water to the circuit

If the problem with the Navien gas boiler is more complex and involves a breakdown of the sensor, pump or automation unit, it is better to contact a service center.

03-04 – ignition is not performed

If the flame does not ignite, a spark does not occur, or the combustion occurs unevenly, “pulsates,” code 03 may appear. Sometimes it looks different: the flame flares up and immediately goes out.

Possible causes of error 03:

• the connection between the control unit and the electrode is broken;
• breakdown of the sensor or electronic board;
• grounding problems.

The Navien boiler safety system works in such a way that it allows the torch to burn only with a stable air supply from the fan. If the air supply is intermittent, the flame may go out automatically.

What to do:

• check if there is a spark;
• make sure that the electrode is connected to the control unit, that is, it responds to ignition;
• diagnose the operation of the fan;
• see if everything is ok with the grounding.

It also happens that the ignition button does not work due to a power outage - check the shield. Worst of all, if the electronic board fails, you will have to replace it.

05-08 – break in temperature sensor

Often the connection between the sensors and the control board is interrupted, and a false suspicion arises that some components in the system have broken down. For example, code 05 indicates that the connection between the control unit and the temperature sensor has been lost.

This occurs for many reasons, including due to condensation humidity on the contacts of the board or the sensor itself, or due to a decrease in the temperature of the coolant to below +14˚С.

To diagnose the performance of parts, we recommend checking the wiring resistance, and if a problem is detected, replace the NTC sensor installed in the heating circuit

Error 06 appears if there is a short circuit in the temperature sensor circuit. For this reason, both the sensor itself and the control board may fail, so diagnostics of all “participants” in the process should be performed.

A similar problem, but in the DHW system, is indicated by the appearance of errors 07-08 on the display.

18-19 – return temperature sensor errors, 21-22 – at the inlet of domestic water.

Advice: before replacing sensors or submitting the control board for repair, carefully check all connections - often a failure occurs due to a simple break in the contacts.

09 – fan malfunction

If the fan rotation speed drops sharply, namely, drops to 400 rpm and remains in this state for 3 seconds, the protection system will work and ignition will be impossible. If the low speed continues for 10 seconds, the display will show code 09.

The program is configured so that after half a minute it will start the blowing device again. If the speed returns to normal, the boiler will turn on and operate in the selected mode; if not, the self-diagnosis will be repeated

An indicator of 2 thousand rpm indicates a short circuit. Most likely, the board has failed or the fan has broken as a result.

What to do:

• Wait until the unit restarts and tries to fix the error itself.
• If the restart continues to repeat, you need to check the board, wire contacts, and clarify the alternating current data - from 100 to 220 V.
• With normal current parameters and low performance of the blowing device, fan failure is clearly diagnosed.
• Replace the fan yourself or invite a specialist.

The problem may also be that the output filter is dirty. Check for blockages and clean if necessary. Often after this simple action the boiler starts working like new.

10 – failure in the smoke removal system

Code 10 appears if there is an obstacle to the exit of combustion products from the boiler to the outside. The smoke removal process is regulated by a smoke exhauster, which creates draft.

Possible causes of error 10:

• blockage in the chimney, reduction in the working diameter of the chimney pipe;
• complete lack of traction;
• malfunction of sensors;
• resistance in the chimney caused by strong winds;
• pipe icing.

If the hoses are incorrectly connected to the APS sensor or are kinked, code 10 may also appear.

To normalize the operation of the Navien boiler, you need to clean the chimney, adjust the draft within acceptable limits, and replace failed sensors

The influence of wind on the combustion process can be reduced by installing a cap at the chimney outlet. If any actions do not help, you should call a specialist for professional diagnostics, Navien boiler maintenance and possibly replacing the control board.

13 – flow sensor is broken

Error 13 indicates a malfunction of the control board, which can cause a short circuit. If after testing the failure is confirmed, the board requires replacement.Sometimes everything is simpler - contacts simply become loose and need to be tightened.

One of the reasons is “sticking” of the flow sensor inside the heating system. To determine it, you need to turn off the unit, ring the lines, and if they ring, check the position of the sensor

To repair or replace, remove the outer panel and look at the position of the flag: when the boiler is turned on, it should be in the lowered state.

If you turn off the circulation pump, code 13 may also appear. As soon as the pump starts working again, the error can be cleared manually by pressing the “Stand-by” button.

Review of less common errors

We have listed the error codes that most often bother users. But there are other symbols that indicate irregularities in the operation of Navien gas boilers and potential repairs.

11 – failure in the operating parameters of water level or pressure. This error appears on the displays of boilers with automatic make-up. To fix it, you need to turn off the system, check the operation of the water filling valve, remove any remaining water in the pump drain, reconnect the pump and restart the system. If it doesn’t help, call technical service.

12 – absence of flame. There are many reasons, and we recommend acting as for errors 03-04. First, check if the gas taps are closed, if there is power supply and if everything is in order with the grounding.

15 – problems with the control board. If it does not respond to power supply, it requires repair or replacement.

16 – overheating of the system, and any of the components can overheat: fan motor, heat exchanger, pump motor. What you can do yourself: clean the filters and heat exchanger, change the thermostat.After a half-hour “rest”, the unit can be restarted - most likely, it will work.

17 – errors related to the DIP switch. You need to correct the control board settings and restart the boiler.

27 – failure of the pressure sensor. If there is no blockage, you need to check the serviceability of the sensor and fan, and then replace the failed part.

30 – overheating of the smoke thermostat. It is necessary to turn off the boiler, allow it to cool for 30 minutes, then restart. If it doesn’t work, check the fan and air pressure sensor, clean the chimney.

93 – the “on/off” button is broken. You should replace it yourself or call a specialist.

Many problems can be solved independently, which is why the manufacturer provides brief instructions on how to resolve emergency situations.

But if it comes to complex repairs or replacements, it is better to have the unit repaired at a service center, with a subsequent guarantee for new spare parts

If an unknown error code appears on the display of a geyser or floor-standing Navien model, you also need to contact specialists.

Conclusions and useful video on the topic

Explanation of error 02:

Error 03 and how to fix it:

How to disassemble the unit and clean the heat exchanger:

The Navien boiler self-diagnosis system is a faithful assistant even for an inexperienced user who has little understanding of the technical intricacies. Thanks to error codes, you can quickly deal with the unit stopping, which means keeping your house warm.

Before starting operation, we recommend that you familiarize yourself not only with the design and technical characteristics of the gas boiler, but also with the code table carefully provided by the manufacturer.

Please write comments in the block form below.Share your own experience in identifying boiler errors by deciphering the code and eliminating operational irregularities. It is possible that your advice will be extremely useful to site visitors.