Plumbers warn homeowners about toilets, pipes freezing in cold temperatures —and what not to do if it happens

The intense cold front and powerful winter storms sweeping across the country are affecting areas not typically accustomed to such frigid temperatures, including Houston.

In these arctic conditions, freezing pipes are always a concern—especially in what’s arguably the most important room in the house: the bathroom.

Here’s what you need to know about frozen toilets and pipes, plus tips on thawing them out enough to get things flowing again.

Can toilets freeze in cold weather?

In a word, yes.

“The water in the toilet and the tank can freeze in extremely cold weather, especially if the toilet is in an unheated space like a cabin or garage,” says Robert Mazzacone, owner of Mazzacone Plumbing and Heating in Westchester, NY. “Any time there is water, it has the potential to freeze.”

So what temperature would a toilet freeze at?

“Water freezes at 32°F, but pipes often need a longer period of cold temperatures below that before freezing becomes a significant risk,” Mazzacone says. “I would estimate around 20°F or lower.”

This risk increases if the pipes connected to the toilet are exposed to cold air, such as in crawl spaces, exterior walls, or poorly insulated sections of the home, according to Jordan Fleming from That HVAC Guy and Plumbing in Philadelphia, PA.

“Frozen water can cause the toilet to crack, while freezing in the pipes connected to the toilet can lead to blocked water flow and, in severe cases, even cause the pipe to burst due to the expansion of ice,” says Fleming. “This is a costly problem for home owners due to pipe repairs and water damage restoration.”

You can’t flush your toilet once it’s frozen

Once a toilet or pipes are frozen, don’t try to flush.

“If the water in the tank or bowl is frozen, the flushing mechanism won’t function properly,” says Fleming.

Attempting to force a flush can damage internal components and pipes, causing even further damage—so you’re better off not using the toilet altogether.

How to keep toilet pipes from freezing

There are a variety of things you can do to help prevent pipes and toilets from freezing in the first place.

• Keep the heat on. “Ensure the thermostat in your home is set to at least 55°F, even if you’re away,” says Fleming. “This helps maintain a safe ambient temperature. Smart thermostats have safety precautions to make sure your unit turns on if the temperature ever gets below the temperature you designated.” No heat? No problem. “You can put a space heater in the bathroom or next to the toilet to prevent freezing—but only if you’re home,” says Ryan Osterkamp, owner of Quality Comfort Home Services in Cincinnati, OH. “Be sure to monitor the space heater closely, as they are not safe to operate unattended.”
• Insulate pipes: “Use foam pipe insulation or heat tape to wrap pipes near the toilet, especially those exposed to cold air in basements, crawl spaces, or exterior walls,” advises Fleming.
• Seal drafts with caulk or weatherstripping: “Close gaps or cracks around windows and doors to prevent cold air from reaching your plumbing systems,” says Mazzacone.

• Let faucets drip: “Running a small trickle of water through your faucets reduces pressure in the pipes and helps prevent freezing,” says Fleming.

  Add antifreeze: In unoccupied or seasonal homes, nontoxic RV antifreeze can be added to toilets and traps to prevent freezing, according to Mazzacone.

• Open cabinets: “Open bathroom doors and vanity cabinets to allow warm air to circulate around pipes,” says Fleming.
• Shut the water off: If you’re going on a winter vacation, take the extra measure to turn off your home’s water completely so unused water won’t freeze and bust your pipes while you’re gone.

Will a frozen toilet pipe thaw on its own?

A frozen pipe will eventually thaw on its own when the temperature rises, but there is a chance that the pipe could burst before thawing.

“It’s best to thaw the toilet safely before attempting to use it,” Fleming says—but turn off the water at the main shut-off valve first. “I recommend using a little electric space heater to help thaw the toilet.”

Don’t have a space heater? You can always use a hair dryer, heat lamp, or a heating pad in a pinch. (But never, under any circumstances, try to thaw a frozen pipe with an open flame or anything flammable.)

Once the toilets and/or pipes are thawed (which may take up to 24 hours), check everything over to be sure nothing is cracked or leaking.

“If you notice any water pooling or dripping, then it would be time to call a plumber to see what damage may have been caused by the freeze,” advises Osterkamp.

If a pipe has indeed burst, it can cost big bucks. According to the Hartford Insurance Co., the average claim for damage from a frozen pipe is $18,000.

You might even have to call in a water remediation company to dry things out and prevent mold later.