How To Thaw a Frozen Tankless Water Heater? Fast and Easy Ways

Thaw A Frozen Tankless Water Heater

If you live in a cold climate, then you know the importance of a reliable water heater. But what happens when your tankless water heater freezes? Here’s a quick guide on how to thaw a frozen tankless water heater so you can get back to enjoying hot water in your home.

Why might your tankless water heater freeze?

Tankless water heater systems are great for providing hot water on demand without any storage requirements. However, like any system, it’s always good to be aware of possible problems that can occur with them and one of these is the potential for freezing in cold climates!

The main cause is a lack of proper winterizing procedures: if not done properly the water supply lines can become exposed to freezing temperatures, causing them to freeze and completely stop the flow of water. Fortunately, this issue can easily be prevented by properly insulating all exposed pipes before cold weather sets in, and routinely checking their insulation even during mid-winter. Taking these simple precautionary measures will ensure your tankless water heater runs reliably no matter what the temperature outside is.

How To Thaw a Frozen Tankless Water Heater

Yikes, your water heater is entirely frozen. We feel for you as it must be freezing outside! And unfortunately, this implies that no warm water will come out of the tap. It’s a shame we can’t make ourselves some comforting hot cocoa right now! That being said, let’s discuss how to fix a blocked-off water heater.

Before you start the thawing process of your frozen water heater, ensure that it is completely off first. It’s essential to turn off its power source and close any gas or water shutoff valves as a precautionary measure. To determine which section needs defrosting, inspect for frost on the pipes surrounding it and feel if there is coldness still lingering in your unit; these are telltale signs of freezing. Just bear in mind that when one area freezes up, other regions nearby can also become impacted by frigidity too!

Prior to beginning the thawing process, inspect your heater for any signs of cracks or pipe ruptures. It may sound peculiar, but freezing water can cause pipes to expand and ultimately burst due to a lack of space in the heater. If you observe any broken pipes or other damages contact your plumber immediately.

To defrost the frozen section, a blow dryer or space heater is recommended for an even thaw. A blow torch may seem tempting to speed up the process but should be avoided as it can create problems with open flame near pipes. Apply heat patiently and evenly across all affected areas; if done correctly, there will likely be no need for noticeable cracks or bursts when finished. Once you believe everything has been sufficiently thawed out from head-to-toe of your unit, switch back on the heater to test that your hard work paid off – however if issues are still apparent after this step then turning it off again would be wise.

We commend you for making it this far with such a tedious process. However, if thawing the pipes does not restore your heater (which can be common in especially cold climates), simply detach the unit from any piping and move it to an area where melting won’t cause destruction – like near a space heater! As the water begins to heat up again, melted material will likely run out of its system creating quite a mess. Keep that in mind before relocating and stay safe!

After successfully thawing the heater, you deserve a round of applause (even though no one is around to hear it)! Plug the unit back in and switch on your trusty appliance – now go ahead and enjoy that hot cup of cocoa. You have earned it!

How Do You Prevent A Tankless Water Heater From Freezing?

Now that we’ve gone through the labor-intensive process of thawing your water heater, let’s do our best to ensure it’s an experience you won’t have to endure again. We’ll explore how to make sure this is one memory we don’t repeat and if ever necessary, at least this time around, be extra prepared!

Draining The Water Heater

Freezing temperatures can cause significant damage to your water heater, but there are steps you can take to prevention. If you keep a slow and steady flow of water running through the system, it helps guard against freezing. We suggest keeping hot water faucets on low rather than cranking them up high – this will provide just enough circulation without wasting gallons of unnecessary H2O.


Insulation is essential in preventing pipes and heaters from freezing. To ensure optimal insulation, you should use both Heat Tape and Fiberglass to provide warmth to the unit itself. Additionally, employing a Heating Cable or Wrap Insulation will form an armor of protection around your piping system. Investing in quality insulation can save you countless dollars on costly repairs down the line!

Power Source

To ensure your tankless water heater’s protective system works, it must be connected to a power source or plugged in. If you are prone to experiencing periodic blackouts, think about getting an emergency generator or simply draining the water heater once the electricity goes off.

Heater Positioning

It’s more important than you may think! Strategic positioning of your water heater is essential for it to work efficiently and not be left vulnerable to the cold. Place the heater in a spot that receives sunshine during most of the day, or somewhere where temperatures are kept at an appropriate level. This will help protect against freezing – trust me, this precautionary measure will save you from future headaches down the road.

Recirculation System

Considering a recirculation system may be the best course of action; however, it isn’t necessarily cost-effective. This innovative technology is designed to transport water quickly and efficiently without waiting for it to heat up – ensuring that the pipes don’t freeze in colder climates due to consistent movement. The water heaters are connected directly to whatever shower or faucet is activated, getting hot water ready in no time!

Regular Maintenance is Vital

It’s crucial to give your equipment routine maintenance, especially for a water heater. To avoid frost or chill issues developing in the future, make sure you check regularly on the pipes and unit of your water heater. Taking these proactive steps will help keep everything running smoothly and efficiently!

Does Cold Temperature Adversely Impact Tankless Water Heaters?

Absolutely not! Most tankless water heaters are designed to withstand temperatures as cold as -20˚F and even colder, with a built-in protection mechanism for those conditions. Therefore, you don’t need to worry about the frigid winter weather taking its toll on your heater’s performance.