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How to Unfreeze Tankless Water Heater: We Provide Expert Guidance

If you live in an area with freezing temperatures, dealing with a frozen tankless water heater can be a common occurrence. But don't worry, with our expert guidance, you can quickly and effectively unfreeze your heater and ensure it operates efficiently during the winter months. In this section, we will provide you with a step-by-step guide on how to unfreeze your tankless water heater, from identifying the causes of freezing to taking the necessary safety precautions and using different unfreezing methods.

Key Takeaways

  • Freezing is a common issue in tankless water heaters, especially in low-temperature regions.
  • Identifying the signs of a frozen heater is crucial for proper troubleshooting.
  • Before unfreezing your heater, it's essential to take safety precautions, such as turning off the power and water sources.
  • Various methods can be used to unfreeze a tankless water heater, including using hot towels and hairdryers, applying heat tape, and using space heaters.
  • Preventive maintenance, such as flushing the system and cleaning the filters, is crucial in avoiding freezing issues.

Understanding the Causes of Freezing in Tankless Water Heaters

Before we delve into the unfreezing process, it's crucial to understand what causes tankless water heaters to freeze. Being aware of these factors could help prevent future incidents and ensure your unit operates efficiently.

Low Temperatures

The most apparent cause of tankless water heater freezing is low temperatures. If the water inside the unit drops below the freezing point, ice will form and cause blockages, preventing water flow. This issue is prevalent in locations with extreme winter conditions, where temperatures drop below the freezing point regularly.

Inadequate Insulation

An inadequately insulated tankless water heater is susceptible to freezing. Insulation serves as a layer of protection against low temperatures, enabling the unit to maintain internal heat. If your heater is poorly insulated, it's more likely to lose heat and freeze during cold weather.

Water Flow Issues

The water flow rate also plays a crucial role in preventing freezing. Inadequate or slow water flow can cause the water inside the heater to stay too long, causing the unit to freeze. Reduced flow rate could occur due to various reasons, including clogged filters, malfunctioning pumps, or damaged valves.

Lack of Maintenance

Lack of proper maintenance can cause various problems, including freezing, in a tankless water heater. Failing to flush the heater regularly, ignoring leaks, or not cleaning the filters could cause the unit to malfunction, leading to freezing.

Poor Installation

Finally, poor installation practices can cause tankless water heaters to freeze. It's essential to have a qualified technician install your unit, ensuring all wiring and connections are correct. Incorrect installation could cause water to freeze in the wrong places, causing damage and reducing the unit's efficiency.

Signs of a Frozen Tankless Water Heater

If you live in an area where temperatures drop below freezing, your tankless water heater can become vulnerable to freezing. If you suspect that your heater has frozen, it is important to identify the signs of a frozen tankless water heater before proceeding with troubleshooting.

Some of the signs that your tankless water heater may be frozen include:

  • No hot water: If you turn on your faucet and no hot water comes out, your tankless water heater may be frozen.
  • Strange noises: Frozen water can cause blockages and generate strange noises from the heater.
  • Water leaks: A frozen tankless water heater can cause water to leak from the unit or pipes connected to it.

If you notice any of these signs, it's important to take action immediately to prevent further damage to the heater and restore hot water supply to your home.

Safety Precautions Before Unfreezing

Ensuring proper safety measures are in place is crucial when attempting to unfreeze a tankless water heater. Failure to do so can result in personal injury, damage to the unit, or even a fire hazard. Here are some essential safety precautions to follow:

  1. Turn off the power supply: Before attempting any form of unfreezing, switch off the power supply connected to your water heater. This action will prevent any accidental electrocution or damage to the unit.
  2. Shut off the water source: Next, shut off the water source to your tankless water heater. This step prevents excess water flow causing short circuits and other electrical hazards.
  3. Familiarize yourself with the owner's manual: Every tankless water heater comes with an owner's manual that outlines vital instructions on how to operate, install, and maintain the unit. It's essential to familiarize yourself with these guidelines to ensure proper handling.
  4. Wear protective gear: Put on protective gear such as gloves and safety glasses to protect yourself from harsh chemicals and burns from hot surfaces.
  5. Avoid using extreme temperatures: Never apply extreme temperatures or naked flames to the unit to hasten the unfreezing process. Doing so can result in further damage to the heater.

By following these precautions, you can ensure a safe and successful unfreezing process. In the next section, we will explore various methods to unfreeze your tankless water heater effectively.

Unfreezing Methods for Tankless Water Heaters

When it comes to unfreezing a tankless water heater, several methods can be effective. The technique you choose depends on the severity of the freezing and the resources at your disposal. Here, we outline some of the most common and reliable methods to unfreeze your tankless water heater.

Method 1: Hot Towels and Hairdryers

This method is best for mild cases of freezing. First, turn off the power supply to the heater and shut off the water source. Then, wrap hot towels around the frozen pipes or use a hairdryer to apply heat. Always keep the heat source moving to avoid damaging the heater, and do not use an open flame, such as a blowtorch, as this can be hazardous.

Method 2: Heat Tape or Space Heaters

If the freezing is more severe, you may need to use a heat tape or space heater. Wrap heat tape around the frozen pipes, plug it in and wait for the ice to melt. Alternatively, position a space heater next to the affected area and wait until the frozen parts thaw. This method is best for localized freezing, and it's essential to monitor the heater and avoid overheating.

Method 3: Water Flow Method

Step Description Step 1 Turn off the power supply to the heater and shut off the water source Step 2 Connect a hose between the hot and cold water valves of the heater, creating a loop Step 3 Pour hot water into the loop created by the hose Step 4 Open the hot water tap closest to the heater and drain the water from the loop Step 5 Reconnect the hot and cold water valves, turn on the water source and power supply

This method is best suited for a specific type of freeze known as a "no-flow" freeze, in which the water stops flowing inside the unit. This technique helps to flush out the ice and enables a smooth water flow through the pipes.

By following these unfreezing methods, you can tackle the freezing issue with your tankless water heater and enjoy hot water all winter long. However, if these methods do not work, it's crucial to seek professional help to avoid further damage to the heater.

Thawing the Water Lines

If your tankless water heater has frozen, it's possible that the water lines have also frozen. Thawing the water lines is crucial for proper water flow and preventing further damage. Here are some effective methods:

Method 1: Apply Heat Tape or Heat Cable

Heat tape or cable is an effective way to thaw frozen pipes. These devices have a heating element that warms the pipes and thaws out the ice. You can wrap the heat tape around the affected pipes, ensuring that it covers the entire length. Once you've wrapped the pipes, plug in the heat tape and wait for a specified amount of time, according to the manufacturer's instructions. Be careful not to overheat the pipes, which can cause damage.

Method 2: Use a Space Heater

You can use a space heater to provide heat in the room where the tankless water heater is located. Place the heater near the heater and turn it on at a low or medium setting. The heat from the heater will warm up the room and thaw the pipes. Be sure to keep the space heater away from flammable objects and never leave it unattended while it's on.

Method 3: Use a Hairdryer

A hairdryer is another effective way to thaw frozen pipes. Hold the hairdryer close to the frozen pipes and move it back and forth until the ice melts. Be patient and continue the process until the water starts flowing freely. Never leave the hairdryer unattended while it's on.

Method 4: Wrap Pipes with Hot Towels

Wrapping the frozen pipes with hot towels can also help to thaw them out. Soak towels in hot water, wring them out, and then wrap them around the frozen pipes. Keep the towels in place until they cool down, and then replace them with fresh, hot towels. Repeat the process until the pipes thaw out and water flows freely.

These are some of the best methods for thawing water lines in a tankless water heater. Remember to follow safety precautions and never use an open flame or propane torch to thaw the pipes. If you're unsure about thawing the pipes yourself, seek professional help.

Checking and Resetting Error Codes

When your tankless water heater is frozen, it may display error codes on its control panel. These error codes help diagnose the specific problem with your system. Checking these codes is crucial to determine the root cause and provide appropriate solutions.

Please note: Different brands and models may have varying error codes and resetting procedures. Consulting your user manual is necessary to ensure proper handling.

Error Code Possible Cause Resetting Procedure EC Power interruption or inadequate gas supply Turn off the power supply and gas valve for one minute. Then, restore the settings and restart the heater. EA Air supply or exhaust blockage or fan motor failure Check the air supply and exhaust vent for blockages. If necessary, clean or replace them. If the fan motor is damaged, call a professional technician for repairs. 032 Flame loss or insufficient gas pressure Check the gas supply line and regulator for damages or obstructions. If the flame sensor is dirty, clean it using a soft brush. If the issue persists, call a professional technician for repairs.

Resetting error codes is often a simple solution to fixing your tankless water heater. However, if the issue is not resolved, seeking professional help is necessary.

Insulating Your Tankless Water Heater

Insulating your tankless water heater is vital in preventing future freezing issues. Tankless water heaters that are not insulated or poorly insulated are more prone to freezing during the winter season. Insulation helps retain the heat within the heater, preventing the water from freezing and ensuring optimal performance even in cold temperatures.

We recommend using fiberglass pipe insulation or foam insulation to insulate your tankless water heater. You can find these materials at most hardware stores or online retailers. Make sure to choose the right size insulation for your heater and follow the manufacturer's instructions for installation.

Steps to Insulate Your Tankless Water Heater: 1. Turn off the power supply and shut off the water source to the heater. 2. Measure the length and diameter of the heater. 3. Buy the insulation material of your choice in the appropriate size. 4. Wrap the insulation material around the heater, starting from the bottom and pulling it up towards the top. 5. Secure the insulation material with duct tape or zip ties. 6. Cut holes in the insulation for any pipes or valves that need to be exposed. 7. Turn the water and power back on and check for any leaks.

Proper insulation not only helps prevent freezing but also improves the energy efficiency of your tankless water heater. This means that you can save money on your utility bills and extend the lifespan of your heater.

Take note: Before insulating your tankless water heater, make sure to consult the manufacturer's warranty to avoid any issues that could void the warranty.

Regular Maintenance to Avoid Freezing

Regular maintenance is essential for keeping your tankless water heater running smoothly and avoiding freezing issues. Here are some key maintenance tasks to perform regularly:

Flush the System

Flushing the system removes any mineral buildup that can cause your heater to work less efficiently. It's recommended to flush the system every six months to a year, depending on the quality of your water supply. To flush the system, follow your manufacturer's instructions or consult a professional technician.

Check for Leaks

Leaks can cause significant damage and affect the performance of your tankless water heater. Regularly inspect the unit for any signs of leaks, such as water pooling around the base. If you notice any leaks, repair them promptly to prevent further damage.

Clean the Filters

Dirty filters can also impact the performance of your tankless water heater. Remove and clean the filters every few months to keep them free of debris. Refer to your manufacturer's instructions for the proper cleaning process.

Inspect and Maintain the Venting System

The venting system is an essential component of your tankless water heater. Regularly inspect the vent pipes and ensure they are free of any debris or obstructions. Any problems with the venting system can cause the heater to shut down or operate at less than optimal efficiency.

Adjust the Temperature Settings

During the winter months, it's tempting to crank up the temperature on your tankless water heater. However, excessively high temperatures can cause the heater to work harder and potentially freeze. Keep the temperature at a moderate level, and adjust it as necessary based on your usage and comfort levels.

Consult a Professional

If you're unsure about performing maintenance tasks on your own or notice any issues with your tankless water heater, consult a professional technician. They can evaluate the unit and recommend any necessary repairs or maintenance tasks.

Seeking Professional Help for Your Tankless Water Heater

If you've noticed that your tankless water heater is persistently freezing or exhibiting other troublesome symptoms, it may be time to seek professional help. While some DIY methods can be effective for unfreezing your heater, certain issues require the expertise of a qualified technician to resolve.

At our company, we understand the importance of a properly functioning tankless water heater, especially during the winter season. Our team of seasoned professionals is well-versed in diagnosing and resolving a wide range of heater-related problems. We have the necessary tools and equipment to ensure a speedy and efficient resolution to your tankless water heater issue.

When you reach out to us for professional help, we will dispatch one of our skilled technicians to your location to assess the problem and determine the best course of action. We pride ourselves on our timely response and providing exceptional customer service, as we are committed to ensuring your complete satisfaction with our work.

So, if you're experiencing issues with your tankless water heater and require professional help, look no further than our team of experts. We are here to help you keep your heater running smoothly and reliably throughout the winter months and beyond.

Tips for Winterizing Your Tankless Water Heater

When winter arrives, it's essential to prepare your tankless water heater for the colder temperatures. By winterizing your unit, you can avoid freezing and other related issues. Here are some tips on how to winterize your tankless water heater effectively:

  • Turn off the power supply: Before starting any winterizing procedure, switch off the power supply to your tankless water heater. This step is crucial for your safety.
  • Shut off the water source: After turning off the power supply, shut off the water source to your heater. This way, you can prevent any water from flowing into the unit while you're working.
  • Drain the water: One of the most crucial steps in winterizing your tankless water heater is to drain any remaining water from the unit. You can do this by connecting a hose to the water outlet valve and draining the water into a suitable container.
  • Use a flushing kit: To ensure that all the water is removed from your tankless water heater, use a flushing kit. This will help you flush out any remaining water in the system and prevent it from freezing.
  • Insulate the unit: Insulating your tankless water heater is essential if you want to prevent any freezing-related issues. By adding insulation to your unit, you can keep it warm and prevent any freezing.

These are some of the most effective tips for winterizing your tankless water heater. By following these steps, you can ensure that your unit operates efficiently through the winter months.

Troubleshooting Other Heater Problems

At times, unfreezing your tankless water heater may not be enough to solve its issues. Several problems may arise, requiring further troubleshooting. Here are some common heater problems you may encounter:

  • No hot water - This problem may occur due to clogged filters, a malfunctioning thermostat, or a faulty heating element. Check these components and replace them if necessary.
  • Fluctuating water temperature - If you experience inconsistent hot water, there may be debris buildup in the heat exchanger or a malfunctioning part. Flushing the system or replacing the faulty part may resolve this issue.
  • Strange noises - Unusual sounds such as popping or hissing could indicate sediment buildup inside the unit or a damaged heating element. Flushing the system or replacing the affected part may fix this issue.
  • Water leaks - Leaks may occur due to a loose connection or a defective part. Check the connections and replace any damaged parts.

If you encounter these or other heater problems, it's best to consult the manufacturer's manual or seek the assistance of a qualified technician. Attempting to resolve complex issues on your own may cause further damage and void the warranty.


In conclusion, we hope that this article has provided you with valuable insights into unfreezing your tankless water heater. By following the step-by-step guidance and understanding the causes of freezing, you can prevent and resolve this issue with ease. Remember, safety precautions should always be taken before attempting any unfreezing methods.

Takeaway Tips

Here are some key takeaway tips to keep in mind:

  • Regular maintenance is essential to prevent freezing issues.
  • Insulating your tankless water heater can help prevent future freezing.
  • Seek professional help if you encounter any complex issues.
  • Winterizing your tankless water heater is important in regions with extremely low temperatures.
  • Always prioritize safety when unfreezing your tankless water heater.

With our expert guidance and your commitment to maintenance, you can ensure that your tankless water heater operates efficiently during the winter season. Thank you for trusting us to provide you with the knowledge and support you need to keep warm!


How do I unfreeze a tankless water heater?

To unfreeze a tankless water heater, follow these steps: [Provide step-by-step guidance here]

What are the causes of freezing in tankless water heaters?

Tankless water heaters can freeze due to low temperatures, inadequate insulation, or water flow issues.

How do I identify if my tankless water heater is frozen?

Signs of a frozen tankless water heater include no hot water, strange noises, and water leaks.

What safety precautions should I take before unfreezing my tankless water heater?

Before attempting to unfreeze your tankless water heater, ensure to turn off the power supply and shut off the water source.

What are the different unfreezing methods for tankless water heaters?

There are various methods for unfreezing a tankless water heater, such as using hot towels, hairdryers, heat tape, or space heaters.

How can I thaw the water lines in a frozen tankless water heater?

Thawing the water lines can be done by [Provide effective methods for thawing the water lines].

How do I check and reset error codes on my tankless water heater?

You can check error codes on your tankless water heater by [Provide instructions for checking error codes]. To reset the error codes, [Provide instructions for resetting error codes].

How can I insulate my tankless water heater to prevent freezing?

Properly insulating your tankless water heater helps prevent freezing. [Provide tips on how to insulate your tankless water heater].

What regular maintenance tasks should I perform to avoid freezing?

Regular maintenance tasks like flushing the system, checking for leaks, and cleaning the filters can help avoid freezing issues.

When should I seek professional help for my tankless water heater?

It's best to seek professional assistance when encountering complex issues with your tankless water heater that you are unable to resolve on your own.

How do I winterize my tankless water heater?

To winterize your tankless water heater, consider draining the water and maintaining appropriate settings during extended periods of non-use.

How can I troubleshoot other problems with my tankless water heater?

If you encounter other issues with your tankless water heater, refer to our troubleshooting tips to resolve them more efficiently.

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