What to Do When Your Pipes Freeze

Here’s how to thaw frozen pipes and avoid having them freeze in the future

By Becky Harris  |  Courtesy of Houzz.com

When you go to turn on your faucets on a frigid day and nothing or only a trickle runs out, it’s the one time you hope you’ve forgotten to pay the water bill. But that’s wishful thinking and you know it, so panic sets in — your pipes are frozen, and if those suckers burst, your house could be a flood zone in no time. Take a deep breath, calm down and follow these steps to thaw them and avoid disaster.


Call in the pros. Don’t hesitate to call in a plumber, especially if you cannot access the frozen pipes. But if it’s 6 a.m., no one is taking your call and you want to get working on the problem right away yourself, here’s what to do.


Turn on the faucets. Turn on each affected faucet. Opening up the flow relieves pressure on the pipes — water expands when it freezes, which can make the pipe burst. Once the pipes start to thaw, the running water can help speed up the melting.


Let water drip. After you tend to these faucets, it’s a good idea to let the rest of your faucets drip, especially the ones that run inside exterior walls. After all, if some of your pipes freeze, it’s cold enough that your other pipes could be vulnerable to freezing as well. Letting them drip helps prevent this.


Warm the room. Turn up the heat. If your bathroom has a little built-in heater of its own or radiant-heat flooring, all the better. Crank them up too.

Open the cabinet doors to let air circulate. “Leave those doors open and let the heat get in,” says Boston area plumber Jim Dellarocco, who has extensive experience with frozen pipes. If you have a space heater, aim it toward the pipes.

Caution: Dellarocco advises being careful if you use an electric heater, as common sense can fly out the window when you’re in a frozen-pipe panic. “Your instinct is to place it as close to the pipe as possible, but don’t do that,” he says. Keep your eye on the portable heater and do not place it somewhere where it could get wet and electrocute you when the water starts to flow, like a shower stall or in a bathtub. If you don’t have a space heater, you can use a heat lamp or Dellarocco’s tool of choice, a blow dryer. 


Heat the whole pipe. If you’re noticing frozen pipes from an upper story, make sure the rooms below (where the pipes run up the wall) are toasty as well. Crank up the heat along the entire length of the pipe. 

If you have a basement, continue checking out that pipe as you go down, as it could be exposed there. Touch the pipes and you may well find the frozen spot. You may see frost on the frozen portion as well. 

Thaw the pipe. The Red Cross recommends using a space heater, a hair dryer or a hot towel wrapped around the pipe to help thaw it out. They also warn not to use a blowtorch, a kerosene or propane heater, a charcoal stove or any other open-flame device. These devices not only could damage the pipes but worse, could cause a house fire. 

Check for leaks. Once things have started to thaw, make sure there are not any leaks. If you can hear a leak, shut off the main water valve and call a plumber. If you don’t hear any rushing water, you can still test it by using your water meter. 

If you have an ice maker, turn it off. Make sure all the toilet tanks have stopped running, make a note of the number on your water meter and set a timer for 30 minutes. Do not use one drop of water during this time. After the timer goes off, check to see if the water meter has shown any use. If it has, you have a leak; call a plumber. 

What if it bursts? If a pipe does burst, shut off the main water valve, call your plumber and insurance company immediately and be sure to take photos of the damage while you’re waiting for the plumber to arrive.


How to Avoid Frozen Pipes — Short-Term Solutions

Locate the shut-off valve for the main water line to your property. If there is a leak or if the pipe does burst, you’ll need to be able to turn it off. 

Take extra care on nights when it’s going to dip below freezing. Dellarocco recommends leaving the heat constant from day to night instead of turning it down when you go to bed. “The few dollars you’ll spend on your bills are a lot better than having to pay plumbers, painters, plasterers and floor refinishers if your pipes burst,” he says. Keep the thermostat at a few degrees higher than you usually would. 

It goes against that water-wasting experiment you did in the second grade, but let your faucets drip overnight.

Keep cabinet doors beneath your sinks open to let the warm air hit the pipes underneath the sink.


Dellarocco says the best way to prevent frozen pipes is to keep your house at a nice, warm temperature around the clock. If you go out of town during the winter, it’s tempting to crank the thermostat way down, but you should keep it set warm enough. The Red Cross recommends a minimum of 55 degrees, but you likely know your house. For example, I live in the South in an older home that is not super-insulated, so I leave it at around 65 degrees. Better yet, if you have a smart thermostat you can control from a mobile device, keep an eye on the temperatures at home online and crank your thermostat up remotely on frigid nights.


How to Avoid Frozen Pipes — Long-Term Solutions

Make sure your home is properly insulated. Uninvited guests like rodents tend to pull down insulation for nests in crawl spaces and attics, so make sure yours is intact before the cold weather hits. 

  • Insulate exposed pipes in spaces like garages, crawl spaces or attics.
  • Drain your hoses and use the shut-off valves or sillcocks (not the frost-free kind) to the outdoor faucets.
  • Consider installing a smart thermostat so you can monitor and control it remotely.

Be vigilant. After 11 years in my home, I know it pretty well. If the temperature has dipped to about 20 degrees or less and the water coming out of my faucets feels extra cold, I go around the house every morning and run each faucet to make sure they haven’t frozen overnight. If you do this and you get no water or only a trickle, it’s highly likely you have a frozen pipe. (If you are also vigilant about not wasting a drop of water, collect it for other uses.)


How to Plan for Resilient Pipes in New Construction

Massachusetts firm ZeroEnergy Design has extensive experience designing energy-efficient homes in places with frigid winters, such as this Passive House in Vermont. Jordan Goldman, an engineering principal there, shared some tips for constructing a house with pipes that won’t be vulnerable to freezing. 

“Implementing these strategies will yield a more comfortable home with improved plumbing resilience and a far lower chance of any pipes freezing, even in the case of a power outage without a generator and/or in the presence of low outdoor temperatures,” he says. 

  • Keep plumbing and HVAC equipment and systems within the home’s thermal envelope whenever possible. (Exceptions include exterior penetrations for life safety, health or code requirements such as plumbing ventilation stacks, heating system combustion exhaust and mechanical ventilation intake/exhaust.)
  • Never install water pipes inside exterior walls, unconditioned attics, unconditioned crawl spaces or basements. (Frost-proof sillcocks are an exception to this rule).
  • Avoid spot air leakage or cold spots inside the house by using both a continuous air barrier, like carefully taped building wrap and continuous insulation around the house exterior.
  • Consider installing an automatic backup generator with the capability of running your heating system during any extended power outages.

“A super-insulated building envelope in a home will almost assuredly keep the house above freezing, even if the heating system or power fails, thus providing exceptional protection against frozen pipes,” Goldman says.