How to Thaw Frozen Pipes

Finding the Frozen Pipe

If temperatures are below freezing and one or more faucets in the house will only put out a trickle, chances are you have a frozen pipe. No pipe material is freeze-proof; PEX is "freeze-resistant" (meaning it's designed to expand and contract with temperature changes without immediate damage), but problems will be encountered after multiple or severe freezing incidents.

If you suspect a frozen pipe, keep any affected faucets open - this will relieve pressure in the pipe and give water and steam an exit route.

• Check other faucets around the house to help narrow down the location of the frozen section. If the entire house is affected, the main supply pipe going into the house may be frozen, or one of its primary branches. If only a section of the house is affected, try to find the line(s) supplying the area by working backwards from the fixtures. If only one faucet is affected, it should be much easier to find the problem pipe.
• Pro Tip: Since you probably won't know the location of the frozen pipe right away, it's a good idea to turn up the heat in the house while you're looking. The affected pipe may be inside a wall or another difficult-to-access location; if this is the case, the time spent trying to track it down could be just enough for the pipe to reach the bursting point. Having additional heat circulating through the home may buy some time.
• Exposed pipes are most susceptible to freezing. Once you have some idea of where the frozen pipe might be, check the exposed pipes in that general area first. These are the ones running through crawl spaces, attics and basements, as well as non-buried pipes coming in from outside. Pipes found inside cabinets that are installed against an outside wall are also at risk.
• Frozen pipes will typically have a frosty exterior, and may even bulge a bit due to the increasing pressure within. With any luck, you won't find evidence of a rupture yet. Carefully inspect not only pipe, but fittings as well.

Thawing Exposed Pipes

If you're able to pin down an approximate location for the ice that's blocking the pipe, there are several options to thaw it. If it's not at all clear within the first 15-20 minutes where the frozen section is, you should seriously consider shutting off the water and calling a plumber - each minute that passes puts more pressure against the pipe walls, and they'll need time to get to you.

Always exercise extreme caution when using any electrical device near water, especially when leaks and puddles are present. Use a Ground Fault Circuit Interrupter (GFCI) outlet, and properly rated extension cords. If there is extensive open water near where you'll be working, avoid the use of electricity altogether: contact a professional, or try the "low-tech" options specified below.

• Leave the house water supply on and affected faucets open when attempting to thaw frozen pipes.
• Hair dryers are a popular thawing tool, delivering hot air that more often than not will melt the ice. Work your way back from the faucet end of the pipe to the frozen section - this gives ice, water and steam an exit, and allows the pressure from incoming water to eventually push what remains of the ice out.
• Heat lamps - like those used to keep food or terrariums warm - are another potential thawing device. The main benefit of using a heat lamp is not having to sit (or lay) in an uncomfortable spot actively working to melt the ice - a heat lamp (or several) can usually be clipped or otherwise situated to direct heat at the pipe while you monitor things elsewhere.
• Small space heaters and utility heaters can also be used when space allows. These generate a good deal of heat, especially in a confined area, and are a good idea if you can't quite pinpoint the affected pipe(s). A small fan can help circulate the warmth around a greater area.
• Helpful Hint: When using hair dryers, heat lamps or heaters on a frozen pipe close to a wall, try sliding a cookie sheet or aluminum foil between the pipe and wall to reflect as much heat as possible toward the pipe.
• Electric heating pads/blankets can safely thaw pipes, as well. Wrap them around the frozen area and wait for the water to start moving. Again, the path to the faucet needs to be clear before the main blockage is dealt with. You can use multiple heating pads, or start at the faucet end before settling on the frozen section, or use one of the methods above while the pad is thawing the affected section.
• Bright Idea! Don't have an electric heating pad? You can go low-tech: saturate towels or blankets with hot water and wrap those around the pipe - although they lose their heat rather quickly, with some effort they should do the trick. Microwaveable heat packs (like those used for sore muscles, etc.) are another excellent option.

Thawing Unexposed Pipes

If the exposed pipes in your home don't appear to be the source of the problem, the freeze has likely taken place in pipes that are inside a wall, the ceiling, or even underground. If you're lucky, you won't have to tear into anything - noticing a frozen pipe early on gives you a chance to successfully thaw it from a distance.

• As mentioned above, turning the house heat up at the first sign of a frozen pipe can help slow down the expansion of ice. Testing out faucets in different areas should help you narrow down the location of the frozen one, or at the very least a specific area of the house - if you have zoned heating, get that area hot! Keep the affected faucet(s) on.
• Helpful Hint: Chances are the wall housing the frozen pipe is an outside wall. Use boards, cardboard, blankets, or something similar to create a temporary windbreak on the outside of the wall to guarantee your heating efforts have maximum impact.
• It's unlikely that central heating alone will be able to thaw the pipe before things get critical. Infrared heat lamps or heaters pointed at the problem area will warm it up better than a standard lamp or heater, delivering more warmth inside the wall where it's needed.
• It may be that the only way to get to the pipe and thaw it out is by removing part of the wall (or ceiling). Nobody wants to do this, but patching up a hole is far more desirable than repairing water damage. Once the pipes are exposed, any of the above methods can be used to begin the thaw (hair dryer, wrapping the pipe with heat, etc).
• Pro Tip: Don't forget the outside: if hoses aren't disconnected and outdoor faucets aren't shut off from the water supply and left open to drain, the pipes that supply them can easily freeze. If a hose has frozen to the bibb, pour warm water over the connection and the pipe until the hose can be removed and water flows again (do not use hot or boiling water, as it could crack the frozen metal). If more cold weather is expected, shut off the supply to that pipe and drain it (or use a freeze cap if the pipe lacks a shutoff valve).

Pipe-thawing machines are primarily used by professionals who need to quickly and effectively thaw out frozen copper or iron pipes (both exposed and unexposed), but they're available to anyone! They work by conducting an electric current through the affected section of pipe, safely melting the ice within. The Hot-Shot models we offer can be used on up to a 175-foot length of pipe, meaning you'll likely never have to open up a wall again.

Should a frozen pipe actually burst, immediately shut off water to the house. If the pipe is in an accessible location, you can then thaw what remains in the pipe, collecting what melts. While the damage to the pipe will have already been done at that point, this will save you from further - and more severe - water damage. You can then decide whether you want to attempt a temporary repair, or call a plumber immediately.

If frozen pipes are a common occurrence on your property, check out our prevention tips. A bit of insulation and/or heat cable may be all you need to keep it from happening next winter!