What Happens If Your Hot Water Heater Freezes?

If you want a comfortable living during the ice-cold winter months, having a functioning water heater is essential. And when it comes to cold weather, sometimes it’s really important to protect the heating equipment from the potential damage caused by the freezing temperatures. 

This applies to hot water heaters as well. If you’ve been wondering about what actually happens when a hot water heater freezes, you’re in the right place. 

During the winter months – and especially in regions that experience extremely cold temperatures – there’s always a risk of your hot water heater freezing. And if this does take place, a couple of different issues can surface. 

If the water pipes freeze, they will expand, eventually bursting your water-heating appliance. There are also potential leaking problems. In terms of performance, on the other hand, the water heater will have to work harder in order to heat the water, which almost always leads to increased energy bills. 

It goes without saying that situations such as these are rarely simple. Water heaters can be at risk of freezing without homeowners knowing about it. 

Are there any symptoms that can indicate a frozen water heater issue? And what can one do to remedy this problem? To find answers to these and other questions concerning this important topic, keep reading. 


What’s the Effect of Cold Weather on a Hot Water Heater? 

Before taking a closer look at all the bad stuff that can happen to your hot water heater once the temperatures drop, let’s see how the cold weather affects this appliance in the first place. 

One very common question among homeowners is when they should start worrying about their water heaters during the cold winter months? And also, what is even the point of these appliances if the water inside of them can freeze so easily? 

To answer the second question, the water inside of these appliances cannot actually freeze that easily – a vast majority of indoor and outdoor water heaters are equipped with some sort of built-in freeze protection. This kind of feature can prevent the water that’s inside the water heater tank from freezing quickly.

However, a professional plumber will always suggest that homeowners still need to take some precautions when it comes to water heaters. The aforementioned freeze protection simply can’t make an appliance of this type completely freeze-proof. 

This, obviously, begs the following question – how can homeowners minimize the risk of their water heaters freezing? 

How to Stop a Water Heater from Freezing? 

Fortunately, there are a number of preventative steps one can take in order to prevent this from occurring. Check out the following freeze prevention tips: 

Insulate the Pipes 

Technician services a water heater

Nobody likes dealing with frozen pipes – there’s no doubt about that. What is more, a frozen pipe is always very susceptible to bursting, which can create an even bigger mess. Add a layer of protection to your pipes by insulating them, and, in that way, prevent this from happening. 

The heater’s built-in freeze protection, which I’ve mentioned above, won’t protect the pipes leading in and out of the appliance – just the water heater itself. For that matter, preventative measures such as these are essential. The more unprotected the pipes are, the higher the chance of them freezing is. 

Fortunately, adding insulation to this part of the plumbing system is an easy DIY task that can be done by pretty much anyone. The most commonly used types of insulation for the pipes are neoprene foam and polyethylene foam. 

If you’re looking for something a bit more specific for your particular situation – or if you don’t want to insulate just the pipes but also your band joists or the crawl space – I would recommend using fiberglass pipe-wrap. In fact, the U.S. Environmental Protection Agency recommends using this type of insulation with gas water heaters. 

If you own an electric water heater, you can’t really go wrong with neoprene or polyethylene foam, though. The process of adding insulation is rather simple, as I mentioned above – it doesn’t require a lot of skill or time. 

Once you’ve measured the pipes, you will only have to cut the insulation so that it fits them and then secure the sleeves. 

Drain the Water 

Draining a pipe
Photo by Thirteen Of Clubs via Flickr (CC BY-SA 2.0)

This particular safety precaution concerns extended vacations and power outages. 

When your water heater doesn’t receive electricity, i.e. when there is no power to it, there will be standing water inside of it. Once we combine this with cold weather, we get cold water that can start freezing at any time and, consequently, expand. As you can already guess, this can have an exceptionally negative effect on the plastic components inside the water heater and lead to further damage down the line. 

That is precisely why the manufacturers of tankless water heaters – one of which is Noritz – advise draining the appliance during a power outage or when the unit is not receiving electricity from a power source. 

Make sure to do this if you’re planning to go on a winter vacation. If you don’t do this, not only can your hot water heater freeze, but also the pipes that are connected to it. 

Keep a Power Source 

Obviously, homeowners don’t have control over all situations. A power outage is rarely something we can see coming – it’s almost always an unexpected case. Homeowners can, however, control how it will affect their homes. 

If experiencing a power outage isn’t that uncommon in your region, it’s essential that you set up some kind of backup system. Using a drain-down solenoid is another way to approach this issue – these are capable of keeping the drain valve closed as long as it’s receiving electricity. 

Once the appliance fails to get power, a drain-down solenoid will open its valve and then drain your water heater. Install this simple device and the water inside your water heater won’t freeze easily. 

Install the Water Heater in a Warm Place 

Water heater in a bathroom

Although the fact of whether you can or can’t do something like this depends on your particular situation, it would be best to install your water heater in a well-insulated area. 

If you’re unable to set up your water heater in a heated space, i.e. into a room that’s heated with some sort of space heater, the unit will be far more susceptible to freezing during the colder part of the year. 

And besides the fact that the water heater can freeze overnight in an unheated area, there will also be a greater chance of you having to deal with the frozen pipes leading in and out of the appliance. 

Thaw Frozen Pipes

Water heater pipes

In case the water inside the heater or inside the pipes is frozen, try thawing the pipes in order to get the water running. But before doing that, make sure to find the water shut-off valve. This is because once the pipes thaw, you may end up with a watery mess. 

Use the thermostat to turn up the temperature and then simply wait until the thawing is over. Depending on the external temperature, this can take as little as half an hour or as long as three or four hours. 

You can also try to directly apply heat to the frozen area with a hairdryer. However, this can take a while and should only be done in case of an emergency. While you’ll definitely have to get quite close to the pipe with your hairdryer, make sure to not touch it directly – just keep the hairdryer running close to the pipe. 

Use a Recirculation System

If you live in a very cold climate, one of your best options would be to use a recirculation system. 

This is a particular type of plumbing system that is capable of quickly and efficiently distributing hot water to a variety of fixtures. With one of these, you’ll never have to wait for your water to heat up. 

How Do I Know If My Water Heater is Frozen? 

Now that you know about the risks associated with frozen water heaters, as well as about the ways in which this issue can be prevented, let’s take a closer look at two of the most common signs that can indicate that your appliance is getting close to freezing: 

Inconsistent Hot Water 

How water running

Inconsistent hot water is undoubtedly one of the first signs of frozen water inside the water heater. Whether it’s not having hot water while washing the dishes or a hot shower suddenly turning lukewarm, you can be sure that there’s something wrong with your water heater. 

Setting the thermostat to a higher temperature is the quickest way to fix this issue. You can do this whenever the weather is reaching unusual extremes and, in that way, adapt to it. 

In the worst scenario, you will have to contact a professional plumber. They will come to your house, inspect the water heater, and try to fix the problem if possible. 

Changes in Energy Bills 

High energy bill

Another sign of potential water heater troubles is an increase in energy bills. After all, appliances like water heaters use a lot of electricity to maintain a steady flow of hot water. And once the temperatures go down in the water, they can struggle to continue doing so. 

However, something like this applies more to the tank-style water heaters – not so much to the outdoor tankless water heaters. As its name suggests, a tank-style water heater stores water inside of its storage tank and has to work harder in order to maintain its temperature. With the heat being lost to the environment, this is undoubtedly a difficult task. 

In other words, whenever the water that’s inside of the unit loses heat, the unit turns on in order to reheat it. To prevent this from happening, make sure to insulate every pipe leading to and from the appliance and also to cover your water heater with an insulation jacket. 

Should I Shut Off My Water Heater in the Case of Frozen Pipes? 

One has to act quickly when the water heater pipes become frozen. It goes without saying that acting right away is bound to prevent additional damage from occurring. However, most people who find themselves in this situation often wonder whether they should turn off their water heater. 

If this happens to you, I would definitely recommend turning off the main water supply valve. Doing this means preventing additional damage from taking place. And once you do this, your best bet would be to simply contact an expert – they will know which steps need to be taken. 

The Takeaway 

Just like all other appliances, water heaters are prone to damage and a variety of other concerns, one of which is water inside of them freezing up. 

And if something like this happens despite your best efforts to prevent it, hiring a plumber is usually the best course of action. After all, plumbing experts have the knowledge – as well as the necessary tools – to safely and effectively unfreeze a frozen plumbing system.