Takagi Tankless Water Heater Error Codes [A Complete Guide]

It’s convenient when instead of concerning yourself with what is wrong with your heater you get a code for specific problems. But it is also confusing to remember which code refers to which problem. 

So, what are the Takagi tankless water heater error codes?

There are multiple error codes for Takagi tankless water heaters. Some of them include, 

  • Error code 031: incorrect DIP switch settings
  • Error code 111: Ignition failure
  • Error code 321: Inlet Thermistor malfunction
  • Error code 991: Imperfect combustion

Once you find out the reason behind this error code, resolving it becomes an easy job. In this article, I have covered all those error codes with their reasons. And from my years of experience fixing Takagi heaters, I have indeed found possible solutions to each problem as well. 

So, before troubleshooting the Takagi tankless water heater by yourself, look for an error code and read this article. 

takagi tankless water heater error codes

Takagi Tankless Water Heater Error Codes [Quick Overview]

The Takagi tankless water heaters are equipped with a built-in diagnostic system for safety and troubleshooting convenience. If there’s an issue with the installation or the unit itself, it will show an error code on both the built-in controller and the remote controller.

Along with the error codes, the computer board’s green LED will flash in a specific pattern. To understand what each error code means, read the next segment of this article.

Here from my first-hand experience, I have provided descriptions for each error code that will help you identify and address any problems. Here are those error codes with their meaning and fixes in short. 

Error CodeMeaningHow to Fix It
031DIP switch setting incorrectAdjust DIP switch settings to match altitude
101Warning for potential error code 991Verify gas type, surroundings, altitude, and system parts
111Ignition failureCheck and clean ignition-related components
121Flame lossCheck and clean ignition-related components
291The DIP switch setting incorrectClear drain system blockages
311Thermistor failure (outlet or heat exchanger)Check wires, inspect thermistors
321Inlet thermistor failureCheck wires, inspect thermistor
331Outlet thermostat malfunctionCheck wires, inspect thermistor
341Exhaust thermistor failureCheck wires, inspect thermistor
391Air-fuel ratio rod failureInspect wires, clean the AFR rod
441Flow sensor malfunctionInspect wires, clean flow sensor
510Solenoid valve (main gas) abnormalExamine wires and computer board
611Fan motor faultExamine wires, clean fan motor
651Flow sensor malfunctionInspect wires and flow sensor impeller
661Bypass valve malfunctionExamine wires, clean valve
701PCB malfunctionCheck wires and connections
711Gas solenoid valve drive circuit abnormalTroubleshoot as per error code 111 and 121
721Communication issue with easy-link systemConfirm proper connections and power
751Abnormal exhaust temperature (indoor models)Adjust temperature settings, inspect components
761Miscommunication with built-in controllerConfirm proper connections and power
941Exhaust temperature issue (indoor models)Check temperature settings, inspect components
991Imperfect combustionCheck gas type, surroundings, altitude, and system parts

Moreover, the error codes are almost similar for all the models of Takagi tankless water heaters with one or two more or less codes. If you are a user of the following models, this article is for you. 

  • H series
  • CT-199
  • 540P (Both Indoor and Outdoor)
  • CX3 Series
  • Series 110
  • HX3 series
  • 910/910 ASME series 
  • 140 Indoor and Outdoor

Takagi Tankless Water Heater Error Codes In Detail

Let’s discuss each error code with its green flash indicator, reasons, and solutions in detail. 

01. Takagi Tankless Water Heater Error Code 031

With the error code 031 in the controller, you will also notice only 1 flash of the green LED on the monitor of your water heater. 

Reason: 

If the DIP switch setting in your Takagi tankless water heater is incorrect, you will notice the 031 error code in the remote control. 

The DIP switch settings need to be adjusted as per the altitude you have set the water heater. If the setting is incorrect, the water heater can’t function properly and will show this 031 code. 

How To Fix It? 

You have to adjust the DIP switch setting to the altitude of the water heater. For indoor and outdoor heaters, the DIP switch settings will also be different. The following pictures will help you with the adjustments. 

i) For indoor Models

indoor models dip switch setting of takagi tankless water heater

ii) For outdoor models

outdoor models dip switch setting of takagi tankless water heater

In these pictures, the correct DIP switch positions are indicated by the dark squares.

As we are talking about the altitude, here’s a thing to remember. According to the manual of Takagi Tankless water heaters, the approved installation altitude varies, with a maximum of 10,100 ft (3,078 m) for indoor units and 6,000 ft (1,829 m) for outdoor units.

02. Takagi Tankless Water Heater Error Code 101

With code 101, there will be 5 green LED flashes in the monitor of your Takagi tankless water heater. 

Reason: 

The error code 101 is not a code for any separate problem, rather it is a warning of the error code “991” in your heater. If you do not address this code immediately, you will face the error code 991. 

How To Fix It? 

To get rid of this error code, you have to follow the troubleshooting steps given below. 

  1. First, verify that the gas type of the water heater corresponds to the type of gas supplied to it. Ensure a proper match in gas type.
  2. Inspect the surroundings of the water heater. Assess the duration for which the unit has been in operation.
  3. Confirm that the altitude DIP switches on the heater are correctly configured to align with the actual installation altitude. The correct setting is mentioned above. 
  4. Examine the intake air and exhaust systems for potential obstructions or blockages. Ensure that both pathways are clear and unobstructed. If you find any blockage in these systems, you have to clean them immediately. 
  5. If the water heater is set up as a direct-vent system, assess the distance between the intake air terminal and the exhaust terminal to ensure it meets the required specifications. The required specification should be in the owner’s manual. 
  6. Investigate the burner and the fan motor for the presence of grease and dirt. This is especially crucial if the water heater has been situated in an environment prone to contamination. If found dirty or greasy, you have to clean the burner of the fan motor. 

03. Takagi Tankless Water Heater Error Code 111

With the error code 111, you will also encounter 3 flashes of green LED on the monitor. 

Reason: 

The ignition failure of your Takagi tankless water heater is responsible for this code 111. When there is an ignition failure in the water heater, the heater can not be activated to heat the water. As a result, the heater shows an error code. All models including Takagi T K3 will also show this code for ignition failure. 

How To Fix It? 

To fix the ignition problem, you have to check and make sure all the ignition-related components are working in good condition. Here is a guideline for this troubleshooting. 

  1. The water heater comes with a safety feature called a “Hi-Limit switch,” which automatically turns off the heater if the temperature gets too high. Because of this safety feature, you only need a relief valve that works based on pressure, not temperature. Make sure the Hi-limit switch is turned On and is working correctly. If it’s not working correctly, you might need to replace it.
  2. Check all the wires for connections and look for any wires that are broken. Also, inspect the computer board for any burn marks, and check the flame rod for any soot buildup. If you find any issues with these components, they may need to be repaired or replaced accordingly. 
  3. Carefully listen for a buzzing sound coming from the burner when the water heater is getting ready to start heating. If you hear this sound, it’s a good sign that the ignition system is working properly.
  4. Pay attention to a double “clunk” sound from the gas valve assembly when the water heater goes into combustion. This sound indicates that the gas valve is functioning as it should. If you don’t hear this sound, the gas valve is faulty and you need to replace the gas valve. 
  5. Check for any signs of leaking from the heat exchanger. If you see any leaks, it’s essential to address them promptly, as they can lead to water damage and affect the heater’s performance. Repairs are necessary in this case. 

04. Takagi Tankless Water Heater Error Code 121

Just like the 111 error code, you will see 3 flashes on the green LED when the error code 121 shows up in the control of your Takagi tankless water heater. 

Reason: 

The reason behind the error code 121 is the loss of flame in the water heater. When the flame goes out, the water heater stops heating the water. As a result, you won’t have hot water. So, your heater will notify you with the error code when it encounters a loss of flame. 

How To Fix It? 

Here are some steps to help you troubleshoot your water heater to fix this error code. 

  1. Make sure the Hi-Limit switch is working correctly. This switch is a safety feature that helps prevent the water heater from overheating. If it’s not functioning properly, it might need to be repaired or replaced.
  2. Examine all the wires and connections in your water heater and the computer board. Look for any signs of damage, such as broken wires or burn marks on the computer board. Additionally, check the flame rod for any soot buildup. Soot can affect the performance of the water heater and may need to be cleaned.
  3. Inspect the heat exchanger for any signs of leaking. The heat exchanger is responsible for transferring heat to the water, and a leak can lead to water damage and reduced efficiency. If you find any leaks, it’s important to address them promptly to prevent further issues.

05. Takagi Tankless Water Heater Error Code 291

Sometimes, with five green LED flashes on your heater monitor, you will notice that the error code 291 has come up in the controller. 

Reason: 

A blockage in the condensate drain system is responsible for this error code 291 appearing. 

Tankless water heaters are designed to be highly efficient by extracting heat from combustion gasses. When the condensate drain is blocked, these gasses cannot be properly vented. It leads to reduced efficiency as the heater may struggle to operate at its intended efficiency levels.

How To Fix It? 

Here are some steps to fix a blocked condensate drain in your tankless water heater.

i) Clear Blockages in the Drain System

Check for any obstructions or things blocking the condensate drain line, the neutralizer (if you have one), and the condensate drain assembly inside the water heater. These parts are usually labeled as parts #416, 421, and 423 Takagi tankless water heater. 

Remove any objects or debris that might be clogging these components.

ii) Ensure Proper Sloping

Make sure that any horizontal sections of the drain line are sloped downward. In other words, the drain line should have a slight slope or incline towards the outlet. This helps the condensate water flow correctly.

If you notice any dips or sags in the drain line where water might collect, correct them by adjusting the slope so that water can drain freely.

06. Takagi Tankless Water Heater Error Code 311

Two flashes of green LED in the monitor with the error code 311 showing up in your water heater can sometimes cause you to panic. 

Reason: 

Depending on the model, the reason behind this code 311 can vary. For example, in 140H/240H/340H Takagi tankless water heater, this code means an outlet thermistor failure. On the other hand, in a 540H water heater, the code means a heat exchanger thermistor failure. 

Basically, your Takagi water heater will either have an outlet thermistor or a heat exchanger thermistor. So, this code means the thermistor is malfunctioning in your water heater. 

How To Fix It? 

To get rid of this code, first, take a close look at the wires connected to your water heater, paying attention to the following:

Check if all wires are properly connected. Ensure that there are no loose or disconnected wires. Examine the wires for any signs of damage, such as fraying, cuts, or exposed wiring. Damaged wires can disrupt the electrical connections in the system.

And after that, you have to check the thermistor. Thermistors (Part #407, 408, 411, 715) are temperature-sensing devices used in water heaters to monitor and regulate the temperature. 

To inspect them, look closely at the thermistors and check for any debris or foreign material that might have accumulated on them. Debris can interfere with their temperature readings. Ensure that the thermistors are securely attached and properly positioned within the water heater. Loose or misaligned thermistors can provide inaccurate temperature readings.

07. Takagi Tankless Water Heater Error Code 321

The 321 error code with 2 green flashes is almost similar to the error code 311. 

Reason:

When you encounter code 321 in your Takagi water heater, that means the inlet thermistor of your heater is malfunctioning, in this case, it doesn’t matter which model of water heater you use. All of them have an inlet thermistor. 

How To Fix It? 

To fix this error code, you have to follow the similar process mentioned under the fixing technique of error code 311. However, instead of an outlet or heat exchanger thermistor, you have to perform the troubleshooting for the inlet thermistor. 

08. Takagi Tankless Water Heater Error Code 331

In some models of water heaters like 540H, you will notice error code 331 with 2 flashes instead of 321 error code. 

Reason: 

When the outlet thermostat is malfunctioning, you will sometimes notice this error code 331 in your Takagi water heater. 

How To Fix It? 

The solution to this problem is also similar to the solution mentioned above in the error code 311 segment. 

09. Takagi Tankless Water Heater Error Code 341

You will only notice this error code with 2 green flashes in your heater when you have an indoor Takagi tankless water heater. 

Reason: 

The reason behind the error code 341 is Exhaust thermistor failure. The indoor model of a Takagi tankless water heater usually comes with an exhaust thermistor. When this thermistor can’t work properly, the heater shows this error code. 

How To Fix It? 

If you want to fix this code, you have to follow the same procedure mentioned above for the exhaust thermistor. 

10. Takagi Tankless Water Heater Error Code 391

This is another combustion problem in the Takagi tankless water heater that comes with 2 flashes in the monitor. 

Reason: 

According to the owner’s manual of Takagi water heaters, the reason behind the error code 391 is a failure in the Air-fuel ratio rod. The air-fuel ratio rod helps regulate the mixture of air and gas entering the burner. 

When it fails, the mixture may become imbalanced. This leads to incomplete combustion and thus comprises the overall performance of the water heater. 

How To Fix It? 

To deal with this error code, first, you have to look for problems with the wires (Part #709). Examine the wires connected to your water heater. Ensure that they are securely connected without any loose or disconnected ends. 

Check the wires for any visible damage, such as fraying, cuts, or exposed wiring. Damaged wires can lead to electrical issues and malfunctions in the system. If you find these types of wiring, replace them immediately. 

After that, check the AFR Rod which is labeled as Part #108 in Takagi tankless water heaters. Look closely at the AFR rod. Check if there is any soot or black residue on the AFR rod. Soot buildup on this component can disrupt its function and affect combustion efficiency. 

If you notice any soot buildup, clean it properly with a soft sponge or vacuum cleaner. 

11. Takagi Tankless Water Heater Error Code 441

If you have a Takagi tankless water heater with an easy-link system, only then you will face this error code with 2 green flashes on the monitor. 

Reason: 

The reason behind the error code 441 in your Takagi tankless water heater is a broken malfunctioning flow sensor. Flow sensors are essential components that detect when hot water is needed. If the sensor fails, the heater may not activate, leaving you with cold water.

How To Fix It? 

To fix the error code and deal with the flow sensor, you have to operate the following troubleshooting process. 

i) Inspect Wires and Flow Sensor Impeller

Check the wires (Labeled as Part #402) for any issues like loose connections or damage. You have to tighten those loose wires properly. If the wire is damaged, replace them.  Look at the flow sensor impeller (labeled as Part #402) for any debris or dirt. If they are dirty, clean them properly. 

ii) Ensure Water Valves are Open

Make sure the shutoff valves for both hot and cold water lines leading to the water heater are fully open.

iii) Check the Filter for Blockages

Examine the filter to see if it’s blocked or has debris in it. If there is, you need to clean them properly. Here is the process of doing this. 

Step 1: First, close the manual gas shutoff valve to turn off the gas supply.

Step 2: Turn off the power to the water heater and wait a couple of seconds before turning it back on. Wait for 30 seconds, then turn off the power again.

Step 3: After that, shut off the water inlet valve that supplies water to the heater. If your water heater is part of a system with multiple units, close both the inlet and outlet water valves to isolate the heater. Then, proceed to step 5.

Step 4: Open all the hot water taps in your house. Once the water flow stops completely, close all the hot water taps.

Step 5: Get a bucket or pan ready to catch the water from the large drain plug with a filter. If there are isolation valves, open them to let the water drain out. If you don’t have isolation valves, carefully unscrew the large drain plug to empty all the water from the unit. Don’t lose the O-ring that’s on the large drain plug.

Step 6: Wait a few minutes to make sure all the water has drained from the unit.

Step 7: Now, it’s time to clean the filter. Look for the water filter inside the cold water inlet. Use a small brush to remove any debris that might have been collected on the filter. After cleaning, put the filter back into the cold water inlet.

Step 8: Carefully screw the drain plug back into place. Hand-tighten it only; you don’t need to use any tools.

12. Takagi Tankless Water Heater Error Code 510

Sometimes, there can be continuous 6 flashes with the error code 510 in your heater which can make you worried. 

Reason: 

If the solenoid valve of the main gas functions abnormally, you will face this particular error code 510. 

How To Fix It? 

Examine the wires connected to your device, specifically those labeled as Part #708. Ensure that they are securely attached and not loose. Check the wires for any visible damage, such as fraying, cuts, or exposed wiring. Damaged wires can disrupt the proper functioning of your device.

Also, look closely at the heater’s computer board. Search for any burn marks or darkened areas on the board’s surface. If the computer board is burnt, you have to replace it. 

If instead of the main gas, the other gas solenoids behave unusually, you will notice the error code 551. You have to tackle it in the same manner.

13. Takagi Tankless Water Heater Error Code 611

Your Takagi tankless water heater may sometimes show 4 flashes in the monitor with the error code 611. 

Reason: 

If the fan motor of your Takagi tankless water heater is faulty, you will face this error code 611. 

How To Fix It? 

To address this error code, you have to check the following parts and make sure they are in good condition. 

i) Wires:

Examine the wires connected to your water heater. Make sure they are securely attached without any loose or disconnected sections.

ii) Fan Motor (Labeled as Part:103):

Check the fan motor for any dust or dirt buildup. Accumulated dust can affect the motor’s performance and efficiency. If the fan motor is dirty. Clean it properly. 

iii) Computer Board (Labeled as Part: 701):

Closely inspect the device’s computer board. Look for any burn marks or darkened areas on the board’s surface. Burn marks suggest possible overheating or electrical issues. If there are burnt marks, replace the board. 

iv) Connectors (Labeled as Part:103):

Inspect connectors for signs of freezing or corrosion. Make sure the connectors are clean and dry.  

14. Takagi Tankless Water Heater Error Code 651

If you are an Easy-link system user, you will see this error code with 4 flashes on the display. 

Reason: 

A malfunction in the flow adjustment valve is responsible for this error code 651. If the valve is faulty, it will adjust the flow rate correctly. This will result in inconsistent hot water temperatures.

How To Fix It? 

To fix this error code, you have to check the flow adjustment valve and make sure it is working in the precise condition. Here’s what you need to check. 

i) Inspect Wires:

Examine the wires connected to the valve. Ensure they are securely attached and without damage. 

ii) Scale Buildup:

Check the valve for any buildup of scale, which is mineral deposits that can accumulate and jam the valve’s motor.

iii) Water Leakage:

Look around the valve for any signs of water leakage. If you see water seeping from the valve, it can be a sign of a leak or faulty seals, which need to be addressed.

15. Takagi Tankless Water Heater Error Code 661

If you are a user of some particular models of Takagi Tankless water heaters, like 540H, you will notice this error code in your monitor with 4 flashes. 

Reason: 

A fault in the water heater’s bypass valve causes this error code 661 to show up.  Bypass valves are used to regulate the flow of water through specific sections of the heater, which in turn affects the temperature of the water delivered to your faucets and appliances. 

If the bypass valve is faulty, it may not adjust the flow correctly. Which will result in inconsistent hot water temperatures.

How To Fix It? 

To get rid of this error code, you need to check the bypass valve of your water heater and make the necessary changes. Here’s what you need to do. 

i) Inspect Wires:

Examine the wires connected to the valve to ensure they are securely attached and not damaged.

ii) Scale Buildup:

Look at the valve for any scale buildup, which is mineral deposits that can accumulate and potentially jam the valve’s motor. If you find scale-buildups, it need to be de-scaled properly. 

iii) Water Leakage:

Examine the area around the valve for any indications of water leakage. If you notice water seeping from the valve or around it, it may be a sign of a leak or problems with the seals, which need to be addressed by consulting a professional. 

16. Takagi Tankless Water Heater Error Code 701

If you ever notice the error code 701 in your water heater with only 1 flash in the green LED, that means there is a problem with the PCB. 

Reason: 

When the computer board in your Takagi tankless water heater is malfunctioning, you will notice this code 701. 

How To Fix It? 

Take a close look at the wires inside your computer board which is labeled as part 714. Examine them to ensure they are securely attached and not damaged in any way.

17. Takagi Tankless Water Heater Error Code 711

Unfortunately, if you notice the error code 711 with one flash in the monitor screen, you have to troubleshoot multiple issues. 

Reason: 

The drive circuit of the gas solenoid valve in your water heater can sometimes fail to function. Which causes this error code 711 to show up. 

How To Fix It? 

To fix the error code 711, you have to troubleshoot in two ways. First, you have to follow the troubleshooting procedure mentioned above, in the solutions to error code 111. 

After that, if the code persists, you have to follow the troubleshooting procedure mentioned under the solutions to the error code 121. 

18. Takagi Tankless Water Heater Error Code 721

When you experience the error code 721 in your Takagi tankless water heater, you will notice 6 LED flashes with it. 

Reason: 

The reason behind this error code 721 is a false flame detection by your water heater. In a gas-powered water heater, a false flame detection can occur when the flame sensor incorrectly signals the presence of a flame when the burner is not actually lit, or when there is no real fire. This can lead to safety concerns and equipment malfunctions.

That’s why the heater warns you about it with the error code. 

How To Fix It? 

To get rid of this false flame error code, you have to perform the following troubleshooting method. 

i) Look for the Condensate Drain

In indoor water heater models, there is a condensate drain installed on the vent collar. This drain helps manage and remove excess moisture produced during the heating process. Ensure that it is correctly in place and not clogged to prevent moisture-related issues.

ii) Inspect for Heat Exchanger Leaks

The heat exchanger is a crucial component responsible for heating the water. Check it carefully for any signs of leaks, which might appear as water seeping from the heat exchanger

If you notice any leaks, you have to replace the heat exchanger and install it correctly to make sure there is no water seeping or leaking. 

19. Takagi Tankless Water Heater Error Code 741

For this error code, you won’t see any green LED flashes on the screen. You will just get the error code on the remote control. 

Reason:

This error code 741 arises when the water heater and the remote control can’t communicate properly or there is a miscommunication between them. 

How To Fix It? 

To ensure proper communication between the heater and the remote control. You have to take the following actions. 

i) Check Your Remote Controller Compatibility

Start by confirming that you are using the right remote controller that’s designed for your specific water heater model. Different models have different remote controllers.

ii) Inspect the Connections

Examine the connections between your water heater and the remote controller. Ensure that all the cables and wires are securely connected. Loose or disconnected connections can disrupt the communication between the controller and the heater.

iii) Check the Power Supply

Verify that the water heater has a consistent and reliable power supply. A lack of power can prevent the remote controller from functioning correctly. Check if the heater is receiving electricity and that it’s properly powered.

20. Takagi Tankless Water Heater Error Code 751

For this error code, you won’t notice any green flashes on the heater screen either. Only the code will appear on the remote. This problem only occurs in the indoor Takagi water heater models only. 

Reason: 

This error code 751 appears due to the lack of proper communication between the water heater and the built-in controller inside the heater. 

How To Fix It? 

Here’s how to enable propeller communication better between the controller and the heater. 

i) Check the Connections to the Built-in Controller

First, take a close look at the connections between your water heater and its built-in controller. Ensure that all the cables and wires are securely connected.

ii) Inspect the Heater Power Supply 

Next, check if the water heater has a reliable and consistent power supply. Make sure it’s properly powered with electricity.

21. Takagi Tankless Water Heater Error Code 761

This is another code where you will not notice any green LED flashes on the screen. It happens only on the heater models with easy-link connections. 

Reason: 

When there is a miscommunication between the heater and the easy-link connection, code 761 appears on the remote control. 

How To Fix It? 

If you want to ensure proper communication with the easy-link system, here’s what you need to do. 

i) Confirm the Connections

Start by verifying that the connections between the main unit (parent unit) and the subsidiary units (child units) are properly configured and connected. The specific setup instructions vary in every water heater model. So, to find out the specific connection to your water heater model, check the owner’s manual. 

ii) Check Heater Power

Check that all the heaters are powered and turned on. Confirm that they are receiving electricity and functioning. 

22. Takagi Tankless Water Heater Error Code 941

When this error code appears on your heater monitor, you will notice 5 LED green light flashes with it. 

Reason:

The reason behind this error code 941 is the abnormal temperature of the exhaust. This error code only appears in indoor models. 

How To Fix It? 

To get rid of these error codes, follow the steps explained below. 

i) Temperature Setting and Recirculation

First, verify that the temperature setting is not higher than 140 °F (60 °C) when the system is in recirculation mode. Setting the temperature too high in this mode can lead to overheating and potential issues. So, this temperature adjustment is important. 

To adjust the temperature in the Takagi water heater, look for the control panel. On the control panel, you will find buttons or dials for adjusting the temperature. This looks for buttons signed “Up” and “Down with hot and cold written on them respectively. You can adjust the temperature by pressing those buttons and to confirm the temperature, you can check the monitor above. 

ii) Inspect the Fan Motor and Wires

Check the fan motor for any dust or debris buildup. Clean the fan motor as required. Additionally, look for loose or damaged wires in the system. Loose connections or damaged wires need to be addressed promptly.

iii) Exhaust Hi-Limit Switch Wires

Examine the wires connected to the exhaust hi-limit switch. Make sure these wires are securely attached and free from any damage. 

23. Takagi Tankless Water Heater Error Code 991

For a gas tankless water heater like Takagi, this error code appears to be very common. With this code, you will notice 5 flashes on the monitor. If you see this code, that means your water heater has stopped working and you will find no hot water in your Takagi tankless water heater.

Also, you will notice that the heater is not turning on even if you provide proper power. 

Reason: 

When your tankless water heater is facing imperfect combustion, the error code 991 will show up in the remote controller. 

How To Fix It? 

To deal with this imperfect combustion issue, you have to check the following items and fix them accordingly. 

i) Gas Type Check

First, make sure the type of gas your water heater uses matches the gas supplied in your area. Mismatched gasses can cause problems.

ii) Environment Inspection

Examine the area around your water heater to see if there are any issues. Also, consider how long the unit has been installed.

iii) Altitude Check

Check the altitude or elevation of the location where the water heater is installed. Altitude can affect its performance.

iv) Intake Air and Exhaust Check

Look for any blockages in the intake air and exhaust. If there is any, clean it properly to get rid of the blockage. 

v) Direct-Vent System Distance

If your water heater is set up as a direct-vent system, ensure there is enough space between the intake air terminal and the exhaust terminal.

vi) Burner and Fan Motor Inspection

Examine the burner and fan motor for any grease or dirt buildup, especially if the water heater is in a contaminated environment. If these components are greasy or dirty, you must clean them properly. 

FAQs:

What is error code 111 on Takagi TM 1?

Error Code 111 indicates a problem where the burner fails to ignite. This issue can result from various factors. It might be due to an insufficient gas supply or an improper gas valve setting. Another possibility is that your Takagi unit has a malfunctioning igniter or a blown fuse.

How do you reset a Takagi tankless water heater?

To reset the Takagi tankless water heater, first, find the reset buttons on the computer board.  Press and hold INC and DEC simultaneously until the red LED lights up. Turn off the unit and then back on to reset your water heater.

What is error code 11 on Takagi?

Error code 11 on Takagi signifies an ignition failure. To resolve it, ensure the Hi-limit switch functions correctly and inspect wires, the computer board, and the flame rod for issues like burn marks or soot.

Conclusion

Here is the complete guideline for Takagi tankless water heater error codes. This article covers all the error codes that you may possibly encounter with Takagi water heaters. 

If you are not experienced with resolving water heater issues, it is highly recommended to consult a professional for this job. 

Now it’s time to say goodbye. Have a nice day and if you’re interested then check a related article – Takagi tankless water heater no hot water.

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