Should I Turn Off the Water Heater if Pipes Freeze?

Living in a very cold environment presents many challenges, and even if you aren’t dealing with an actual survival situation, common cold weather emergencies can still threaten your home.

frozen water tap

One of the very worst things that can happen is your pipes freezing. Try as we might, sometimes the weather just gets too bitterly cold for our pipes to withstand it.

When that happens, you’ve got real problems and you need to take action fast to prevent disaster or keep the damage from getting worse. On that note, should you turn off your water heater if your pipes freeze?

Yes, you should turn off your water heater if your pipes freeze. Conventional tank water heaters should always be turned off, but tankless water heaters may or may not need to be turned off depending on the manufacturer’s specifications.

Failing to turn off your water heater when your pipes freeze might lead to a destroyed heater and potentially a dangerous condition that could result in an accidental fire.

It’s just one more thing you’ll have to remember to do if your pipes start to freeze up, but doing it will prevent the situation from getting worse. Keep reading and we will tell you more.

Why Should You Shut off the Water Heater When Your Pipes Freeze?

If your pipes freeze, they can burst, crack or pop a joint and start leaking. This could lead to a loss of water in the tank of the water heater which will then malfunction.

Once you have confirmation that your pipes are frozen, shut down your water heater right away.

How Will You Know Your Pipes are Frozen?

When the weather turns really cold, it is easy to wonder if your pipes are going to freeze, in the process of freezing, or already frozen. Luckily there is a way to find out by performing simple diagnostics.

First, try the faucets inside your home. If there’s any faucet in your home that has no water flow, very little water coming out, or just a noticeably reduced amount of water then you know that the pipe leading to that particular faucet is already frozen or is starting to freeze respectively.

Pipes that are frozen solid will only deliver a reduced amount of water or water that flows sluggishly, impairing the flow coming out of the faucet.

Next, inspect the pipes themselves wherever they are. If you see a significant amount of condensation on the pipes, they could be frozen and any sign of frost on the pipes is a sure indicator that they are already frozen or will freeze in the near future.

If you are still uncertain, grab yourself a reasonably lightweight metal implement but one that has some heft to it.

You don’t want to damage your pipes, but tap on them gently with your chosen tool and listen to the tone. A ringing, reverberating or hollow sound means the pipes are probably clear, or clear enough. A solid tone or thunk means they are frozen.

However, you managed to confirm that the pipes are freezing or already frozen, take action immediately.

If Your Pipes Freeze, Shut Off the Water Right Away, then the Water Heater

The very first thing you must do is shut off the water supply coming into your home. Here’s hoping you know where the nearest appropriate shut-off is and that you have maintained it so that you know it is functional.

Next, head to your water heater and shut it off, and also stop the gas flow to it in case of a gas water heater. Doing this ensures that you’ll prevent damage if the water level in the tank drops.

Tank Water Heaters Should Not Be Heated With No Water Inside

The reason you want to shut off your water heater when your pipes freeze is, as mentioned, because this might prevent the tank from refilling and maintaining the required water level for normal function.

This is crucially important because water heaters should not operate, meaning apply heat, if there is no water inside. This isn’t a matter of waste: it’s a matter of safety.

The water, though we are heating it up for normal usage in our home, also acts to distribute the immense heat generated by the water heater.

The components and coatings inside the tank are not designed to withstand this heat without the water there as a sort of insulator and mediator.

Water heaters that are allowed to empty, or partially empty, and still operate will routinely destroy themselves and it isn’t out of the question that something could melt or catch fire and potentially exit the enclosure of the tank, maybe even starting a devastating house fire.

That is the very, very last thing you need under the circumstances! Luckily, this is easy to prevent by simply shutting down the water heater at the first sign of frozen pipes.

Tankless Water Heaters Might Be Kept On

It is always a good rule of thumb to shut off your water heater when the pipes freeze, and there are no exceptions for traditional tank-style water heaters.

However, depending on the design and specifications of your tankless water heater or on-demand water heater as they are sometimes called you might not need to shut them off since they don’t hold and heat a vast quantity of water the same way that the more traditional style does.

Always refer to your manufacturer’s instructions in the manual and follow them. This is no time for improvisation or second-guessing!

If the manufacturer says that you can leave your tankless water heater on when the pipes freeze or when water service is interrupted, then you can. If they say, however, that you should shut it off, definitely do!

Insulate Pipes to Help Prevent Freezing

You can potentially avoid this whole unfortunate mess in the first place by protecting your pipes from cold weather.

The easiest and most direct solution is to insulate your pipes using specialized or improvised pipe insulation.

Other good options are pipe heaters which are specially designed for the purpose, or if you have pipes in a smaller compartment or passageway of your home that is accessible you might consider placing a small space heater in there, safety allowing, in order to keep the pipes warm and the water flowing.

This will save you a major headache of course by preventing them from freezing in the first place, and also potentially save your water heater.

Always Call a Plumber to Assess Damage to Frozen Pipes

No matter what happens or does not happen, if you know your pipes have frozen solid it is always in your best interest to call a plumber in order to assess the damage.

This can save you a ton of grief and even more money over a potential flood if they start leaking after they thaw.

If your water heater emptied, or you suspect that it emptied, during the whole fiasco have your plumber inspect that too for proper function, as they will be able to tell you if damage was likely to have occurred.

1 thought on “Should I Turn Off the Water Heater if Pipes Freeze?”

  1. in my experience, turn off the main water valve to reduce pressure. that way you will not flood the house when the pipes thaw. I would keep the hot water heater on so it doesn’t freeze. I like pex waterline cause they will not burst when it freezes.

Leave a Comment

Your email address will not be published. Required fields are marked *