How to Protect Tankless Water Heater From Freezing

Are you looking for ways to protect your tankless water heater from freezing this winter? Living in a cold climate can make it difficult to keep your system running efficiently. If not properly insulated or maintained, the danger of freezing pipes and potential damage increases during these chilly months. That’s why protecting your tankless water heater from all possible kinds of damage is essential for optimal functionality and performance – both now and in the future. 

How to Protect Tankless Water Heater From Freezing

Tankless water heaters are a great way to save energy and money while providing an endless hot water supply. However, if exposed to cold temperatures, they can become damaged or even freeze up completely.

In this blog post, we’ll discuss the necessary steps you need to take to protect your tankless water heater from freezing during winter months. Keep reading for step-by-step instructions on how to protect tankless water heater from freezing.

What Can Make Your Tankless Water Heater Freeze?

Before implementing any strategy to protect your tankless water heater from freezing, it’s important to understand the factors that can contribute to a frozen tank.

The main factors contributing to a frozen tank are cold weather and temperatures below 35°F. For hot water to be produced, a certain amount of heat must be absorbed from the air and transferred into your water heater. When temperatures drop below 35°F, this process becomes ineffective and can cause your tankless system to freeze.

Aside from cold weather, having an insufficiently insulated tank or exposed pipes can also increase the risk of freezing. If you have outdoor tanks or exposed pipes, it’s important to ensure they are also properly insulated.

What Will You Need?

In order to protect your tankless water heater from freezing temperatures, you’ll need a few simple items:

  1. Insulating material
  2. Pipe insulation tape
  3. Heating cables

Once you have the necessary tools, you can begin to protect your tankless water heater from freezing temperatures.

10 Easy Steps on How to Protect Tankless Water Heater From Freezing

1. Proper Insulation

The first step in protecting your tankless water heater is to insulate all exposed pipes, tanks, and fittings properly. This will help keep warm air from escaping and cold air from entering. It’s also important to check for any leaks or gaps around fittings, as these can also contribute to temperature fluctuations.

 Insulate All Exposed Pipes

2. Heat Tape

If you cannot properly insulate all components of your system, then using heat tape (or heating cables) may be a good option for preventing freezing temperatures in more difficult areas such as outdoor walls and roofs. It will provide continual warmth and can help protect your system from any potential damage. Don’t forget the joints when wrapping; secure them with tape whenever possible.

3. Ventilation

Ensuring your system is properly ventilated is another way to help increase its efficiency and prevent freezing temperatures. It’s important to check air vents regularly and ensure they are not blocked or restricted. Otherwise, warm air may not be able to circulate properly.

4. Drain Pipes

If you have any exposed pipes, then it’s important to ensure that they are properly drained of all liquids before winter sets in. This will help prevent ice from forming inside the pipes and potentially damaging the system as a whole. You can also wrap the pipes with a layer of insulation to help retain heat.

5. Thermostat Settings

It’s also recommended that you adjust your thermostat settings during cold weather months to stay above 35°F. This will help minimize the risk of your system freezing up and potentially damaging it. Ensure that the settings are adjusted properly and regularly monitored.

6. Regular Maintenance

It’s also important to keep up with regular maintenance on your tankless water heater. This includes checking for leaks, ensuring proper venting and insulation, and regularly inspecting all components. Remember, a well-maintained tankless water heater is less likely to freeze.

Regular Maintenance 
on Tankless Water Heater

7. Antifreeze

If temperatures are extremely low or you can’t properly insulate all components of your system, then using an antifreeze solution may be necessary in order to protect it from freezing temperatures. Always consult a professional before attempting to use any antifreeze solution, as improper usage can damage your system permanently. Additionally, make sure to read and follow all directions carefully.

8. Hot Water Circulation

If you’re concerned about freezing temperatures, installing a hot water circulation system may be helpful. This will help keep the water circulating throughout your system and prevent any potential freezing of pipes or components. Moreover, it will also help reduce energy costs as hot water won’t be wasted while waiting for it to reach the tap.

9. Identify Cold Spots

It’s important to identify any areas of your system that are particularly susceptible to cold temperatures and take steps to ensure they don’t freeze up. Doing this can minimize the risk of damage to your system. Be careful when inspecting cold spots, and never attempt to thaw a frozen component with an open flame, as this could lead to further damage.

10. Power Backup System

If temperatures are expected to drop below 35°F, then it’s recommended that you have a power backup system in place in order to continue supplying hot water to your system. This will help ensure that your tankless water heater can operate even when temperatures are below freezing. Don’t forget to regularly check and maintain your backup system in order to ensure that it is operating properly.

Following these simple steps, you can easily protect your tankless water heater from freezing temperatures and keep it running efficiently all winter! By insulating and maintaining your system properly, you can avoid costly repairs or replacements due to freezing temperatures. With the right precautions, you can enjoy hot showers throughout the year!

5 Additional Tips and Tricks

  1. Keep an eye on the temperature outside. If you know how cold it is outside, you can adjust how much insulation you need for your tankless water heater accordingly.
  2. Install a freeze protection valve or thermostat on the hot water side of the system to shut off automatically if temperatures become too low for operation.
  3. Make sure there is proper ventilation inside and outside of your home for your tankless water heater to work efficiently and avoid freezing. Proper ventilation will also help keep the water warm.
  4. Keep the water heater clean and free of debris. Debris, such as dirt, leaves, or snow, can block airflow and cause freezing temperatures.
  5. Install a secondary heat source near your tankless water heater to help keep it running even when temperatures drop below freezing. This could be something like an electric or heated blanket that can keep your tankless water heater warm.
Install a Freeze Protection Valve

Following these additional tips and tricks, you can protect your tankless water heater from freezing temperatures and avoid any damage or disruption to your hot water supply. By taking the necessary precautions, you’ll ensure that your tankless water heater continues to work efficiently for years to come.

5 Things You Should Avoid

1. Don’t Let Your Tankless Water Heater Be Exposed to Cold Temperatures: Cold temperatures can damage internal components in the tankless water heater, reducing its efficiency and performance. Ensure it is located inside a heated area of your home, such as an attic or basement.

2. Don’t Use Outdoor Fittings on Your Indoor Unit: If you have an outdoor tankless water heater, make sure to use approved indoor fittings on it, such as a hose connected directly to the unit. Outdoor fittings are not designed for indoor temperatures and can cause the freezing of the water heater.

3. Don’t Install in Areas That Are Exposed to Cold Air: Cold air coming into contact with your tankless water heater can cause condensation inside the unit, which then freezes and causes damage. Ensure it is installed away from drafts, windows, and doors that open outwards.

4. Don’t Forget to Insulate It Well: Make sure your tankless water heater is properly insulated against heat loss during winter months. This will help reduce how much cold air your unit is exposed to and how much condensation can form inside the unit.

5. Don’t Ignore Maintenance: Make sure you perform regular maintenance on your tankless water heater, such as draining out old water or checking for blockages in pipes and hoses. This will help reduce how often the unit needs to be heated up, reducing the chances of freezing.

Checking for Blockages in Pipes and Hoses

Taking these precautions will ensure that your tankless water heater stays safe and works in cold weather conditions. If you have any questions or concerns about how to protect your tankless water heater from freezing, it’s best to consult a licensed technician before taking any action. Taking extra precautions now may help you avoid costly repairs or replacements in the long run.


Protecting your tankless water heater from freezing is necessary to ensure the system’s longevity and efficiency. We’ve discussed a variety of methods ranging from drain valves and insulating systems, to winterizing procedures, to adjusting overall thermostat settings.

Ultimately, it is important that you choose the best protection for your system, which is not only cost-effective but also compatible with your particular water heating system. Taking care of your tankless water heater will give you peace of mind of knowing that you are taking preventative steps against any potential freeze-related damage.

If you ever feel unsure about any of the steps covered in this blog post, always contact an experienced professional who can help guide you toward the best plan for you and your tankless water heater.

Hopefully, this article has been helpful in providing you with information on how to protect tankless water heater from freezing. Thanks for reading!

Angela Ervin

Angela Ervin

Angela is the executive editor of DIY quickly. She began her career as an interior designer before applying her strategic and creative passion to lifestyle and home. She has close to 15 years of experience in creative writing and online content strategy for housekeeping, home decorations as well as other niche efforts. She loves her job and has the privilege of working with an extraordinary team. She lives with her husband, two sons, and daughter in Petersburg. When she's not busy working she spent time with her family.

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