Using A Heat Gun To Unfreeze Pipes? 5 Things You Need To Know Before You Do

Frozen pipes are a major problem in winter, particularly for those who endure more bitter cold. When pipes freeze, the water inside starts to expand. If left unchecked, that expanding water will exceed the pipe's capacity, and the pipe will burst. The absolute last thing you want is for a pipe to burst in mid-winter, when leaking water can lead to even more freezing. And if you're experiencing a particularly bitter winter, a plumber may not be able to get to you quickly.

If you've got a bad case of frozen pipes and need them unfrozen as soon as possible, there are ways to handle it on your own. One avenue is a heat gun, a power tool that delivers high levels of concentrated heat wherever you point it. On paper, this sounds like a perfect solution, one just about anyone can do. However, as with any home repair job, you need to take an entire checklist of safety precautions if you don't want to accidentally make things much worse.

While a heat gun may sound like the perfect solution for a frozen pipe, it should never be your first, or even second, resort. Heat guns are heavy-duty tools, intended primarily for professional-level work. While there are reasons everyone should own a heat gun, for DIY projects and the like, that kind of portable, powerful heat generation shouldn't just be slung around at any half-baked opportunity.

If your frozen pipe problem is relatively small in scope, such as a couple of frosty pipes under a single faucet, there are other avenues you can pursue before jumping to a heat gun. A heat lamp or space heater can provide a more reasonable degree of heat over a large area. Or if you absolutely need something that you can hold in your hand, consider a hair dryer. Even a few rags soaked in warm water, carefully draped over the frozen pipes, is safer. Long story short, you should only bust out the heat gun if you don't have any other means of thawing out that pipe.

Heat guns are, unsurprisingly, hot. As in up to 1,000 degrees — more than hot enough to cause damage or fires. The primary reason they shouldn't be your first tool for thawing pipes is that many household pipes are near materials like wood. If you start blasting away with a heat gun with no consideration for what's around a frozen pipe, you could end up setting fire to your house.

Even if there's no wood around the pipe, that doesn't give you a free pass. For example, if the pipe is made of a plastic material like PVC, intense heat could cause it to melt, giving you basically the same result as if it burst. Make sure to only use a heat gun on pipes made of a heat-resistant material like metal, and to employ heat shielding around the pipe, such as aluminum foil or a metal pan, so nothing nearby gets damaged. And have a fire extinguisher handy, just in case.

Before thawing pipes, including by using a heat gun, prep your water system for the upcoming shift in temperature and water pressure. If there's a lot of ice in that pipe, there's going to be a change in pressure when you heat it, and you want that pressure to safely filter out somewhere.

The best way to handle this is to open up any faucets that are connected to the frozen pipe beforehand. Even if the water pressure has been diminished by the freeze, getting a little bit of water flow will help to alleviate any changes in pressure, not to mention slowly begin the thawing process. As you start to thaw out the pipe, the water will begin flowing more readily through it, which will help to melt the ice and carry it away.

Incidentally, keeping faucets open a crack and letting a little water drip is a great way to prevent pipes from freezing in the winter, since the water doesn't stand still long enough to freeze.

Because heat guns deliver so much heat, if you crank one all the way up to full blast, you're more likely to induce thermal shock than anything productive. Have you ever seen someone dump a kettle of boiling water on a windshield to defrost it, only to have the windshield end up cracking? That's thermal shock, the phenomenon that occurs when an object is subject to violently opposing temperatures. (And that's this is one of the defrosting techniques you should never use on your car's windshield.)

If you use a heat gun on a frozen pipe, it's imperative that utilize the lowest setting available. Tools like Harbor Freight's Bauer 14-Temperature Heat Gun have temperature dials you can use to pick exactly how much heat is generated. Turn it down so it's just hot enough that you can feel it, but not so hot that it's scalding.

Water pressure is tricky; if too much is added or alleviated in a single spot, it's going to violently build up somewhere else, and the pipe will burst. This is why, when thawing pipes, it's vital that you do so in a gradual manner across the pipe's full length. By applying heat evenly across the whole pipe's surface, you ensure that the newly flowing water won't get backed up in any one spot.

Doing this with a heat gun can be a bit tricky, as the gun definitely won't be long enough to cover the entire length of the pipe. You'll need to make up the difference, carefully moving it back and forth in a gradual manner so you don't get too much heat in one spot. Some, like the Ryobi One+ heat gun, come with an attachable deflector nozzle. This nozzle functions as a means of delivering heat across a circular area. If you have one of these nozzles and it's big enough to accommodate the whole pipe, you can hook it on and move the gun back and forth to deliver more uniform heat.