Can A Water Heater Freeze? (Find Out Now!)

Matthew Mountain
by Matthew Mountain

Problems with water heaters can be stressful because they are an essential part of modern living. Water heaters are dense and durable, but they are still prone to failure which can prove expensive. So, can a water heater freeze?

A water heater can freeze if the power goes out or it runs out of gas whether it is traditional or tankless. Extreme temperature drops can also cause a water heater to freeze, and you’ll need to drain it to prevent damage. Water heaters are more likely to freeze if they are poorly insulated or located in a cold space.

Frozen water lines can cause your water heater to freeze, and you’ll need to thaw the pipes. Luckily, there are several solutions to a frozen water heater such as draining the tank or using a space heater. Follow along as we explore the factors that cause a water heater to freeze and what you can do about it.

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Can a Hot Water Heater Freeze?

A water heater can freeze if it loses power for a while or runs out of gas. Both traditional and tankless water heaters can freeze, and while it is uncommon, it can occur in freezing temperatures. This is most common during the fall or winter when temperatures plummet.

The lines that carry water to your water heater can freeze, and that can cause the heater itself to freeze. Poor insulation can make it harder for your water heater and lines to stay warm during cold weather, and that can accelerate the process. It is rare for water heaters to freeze, but it is generally due to a combination of low temperatures, poor insulation, and power outages.

Cold weather can not only freeze your pipes but expand them as well. And when a pipe expands too much, it could burst and flood a home with water (if there’s water running at the time). Weatherproof your appliances, especially if you live in a place that experiences cold temperatures often throughout a year. And if you’re worried about the location your water heater is in, consult a professional plumber.

What to Do When Your Water Heater Freezes

It is important to act quickly when your water heater freezes. Water can expand by up to 40% when it freezes and that can damage your water heater and cause your pipes to burst. Let’s take a look at what you should do if your water heater freezes.

Drain It

The best course of action is to drain your water heater when it freezes to avoid further damage. You can reduce the risk of expansion damage if you drain the excess water from the heater, and it will help melt existing ice. Shut off the water supply lines so that water doesn’t continue to flow into the heater and wait until the heater isn’t too hot to touch.

Place a bucket under the drain valve and drain the water from the heater. You can run a faucet while you drain the water heater to help thaw the ice.

Thaw Water Pipes

Thaw your water pipes if they or your water heater are frozen. Turn up the heat on your thermostat and wait until your water pipes thaw out. This can take as little as 30 minutes or as long as several hours to work depending on the external temperature.

You can also use a hairdryer to thaw your pipes directly in an emergency, but it may take a while. Get close enough to the pipes for the heat from the hairdryer to radiate to the pipes, but never touch the pipes directly. Put a space heater near the water heater or frozen pipes and let it run until they thaw.

Electrical Heating Tape

Wrap your pipes with electrical heating tape if they are frozen to help thaw the water heater. It takes at least 10 minutes for electrical heating tape to thaw frozen pipes in many cases. Ideally, your water heater will thaw as the pipes thaw, and you can drain the excess water afterward.

Improve Insulation

Poor insulation can cause your water heater to freeze easily during the winter. Luckily, water heater fiberglass insulation blankets only cost $30 and are easy to install. The insulation will help retain heat and protect the water heater from extreme temperature drops.

You need to insulate the water pipes that lead to your water heater as well. A water heater can freeze even if it is insulated if you don’t protect the pipes themselves. Cover your waterpipes in polyethylene wraps or fiberglass wraps so that they don’t freeze in the future.

You May Need a Recirculation System

Individuals who live in cold climates often utilize recirculation water heaters, as these are designed to make water instantly available. If you’re using a recirculation system in the winter, your water heater will continuously pump water into your home.

This way your pipes are consistently warm and you don’t have to worry about your water heater freezing. However, a recirculation system, because it provides this useful preventative measure, is more expensive than a basic water heater.

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Related Questions

Since all homeowners and most business owners need access to hot water daily, water heaters have been essential appliances. And because they’re so essential, many have questions about them. Some of the frequently asked water heater questions, which relate to this article’s topic, are answered below.

Can a tankless water heater freeze?

A tankless water heater is less likely to freeze, and that’s because it doesn’t include a multi-gallon tank of water. However, if a tankless system doesn’t employ a self-heating function—which most have—and it’s not used for days or weeks, a tankless system could be susceptible to freezing. Thawing out a tankless system is much easier than thawing out a system that utilizes a tank.

Are outdoor water heaters not good?

Outdoor water heaters can work well if they’re installed in a good location outside. Also, it’s best if the area’s climate isn’t frigid throughout most of the year. Most outdoor water heaters are designed with the elements in mind, so they can stand strong in the face of torrential rains, whipping winds, and heavy snowfall.

Matthew Mountain
Matthew Mountain

Matt loves everything DIY. He has been learning and practicing different trades since he was a kid, and he's often the first one called when a friend or family member needs a helping hand at home. Matt loves to work with wood and stone, and landscaping is by far his most favorite pastime.

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