You turn on the tap on a cold morning and nothing comes out, or only a thin trickle. A pipe in your home has frozen. Frozen pipes in winter are one of the most common cold-weather plumbing problems, and the next hour matters. Thaw the pipe the right way and your water comes back. Thaw it the wrong way and the pipe can burst and flood your home.
This guide shows you how to thaw frozen pipes safely, step by step. The short answer is simple: open the faucet, find the frozen section, and warm it gently with a hair dryer, an electric heating pad, towels soaked in hot water, or a portable space heater. Start at the faucet end and work back toward the frozen spot. Keep heating until full water pressure returns. Never use an open flame, a blowtorch, or a fuel-burning heater. That sequence follows the guidance of the American Red Cross, and this article follows it too. Frozen pipe thawing is slow work, and slow is safe. If you want to know how to defrost frozen pipes without making things worse, start with the checks below, then work through the seven steps.
How to Tell If a Pipe Is Frozen
Before you warm anything, make sure the problem is really a frozen pipe. The clearest sign is a faucet that gives you no water at all, or only a trickle, on a freezing day. Turn on every faucet in the house, one at a time. If only one faucet is affected, the frozen pipe is probably on the line that serves that faucet. If several faucets have no flow, more than one pipe may be frozen.
Look at any exposed pipe you can reach. Frost on the outside of a pipe is a strong clue. So is a cold spot: run your hand along the pipe, and the frozen section often feels much colder than the rest. A bulge in the pipe, a wet spot on a wall or ceiling, or a gurgling sound can mean air is trapped behind an ice blockage. A hissing sound near a pipe is more serious, because it can mean water is escaping through a crack. If you hear hissing or see water, skip the thawing steps and go to the section on signs your pipe already burst.
Think about where the cold reaches your pipes. Pipes on an exterior wall, in an unheated basement, in a crawl space, in a garage, or in an attic freeze first. Kitchen and bathroom pipes under sinks on outside walls are common trouble spots.
Before You Touch Anything: 3 Safety Checks
Thawing a frozen pipe is safe only if you prepare first. A pipe can already be cracked behind the ice, and you will not know it until the ice melts. These three checks take five minutes and protect you from a flood.
Check 1: Find Your Main Water Valve
Find your main water valve before you apply any heat. It is usually near where the water line enters your home, often in the basement, near the water meter, or by the front wall. Turn the handle once to make sure it moves. If the pipe has already split, water will start to flow the moment the ice melts, and a working main water valve lets you stop that water in seconds. If you cannot find the valve, or it will not turn, call a plumber before you thaw anything.
Check 2: Open the Faucet
Open the faucet that the frozen pipe serves, both hot and cold handles if it has two, and leave it open for the whole job. An open faucet gives melting water somewhere to go, so pressure does not build up behind the remaining ice. It also tells you when you are making progress: a trickle becomes a steady stream as the ice clears. If you thaw a pipe with the faucet closed, melting water and steam have no escape route, and the pressure can crack the pipe.
Check 3: Look for Cracks, Bulges, and Leaks
Look closely at the frozen section and the pipe around it. A split, a bulge, a pushed-apart joint, or a wet patch means the pipe may already be damaged. If you see any of these, do not apply heat. Shut off the main water valve and call an emergency plumber. Thawing a split pipe with the water still on is how a frozen pipe becomes a flood. Also look at the floor. If there is standing water near the pipe, keep every electrical device away from it. Water and electricity are a dangerous mix, and electrical shock is a real risk when a pipe leaks. Never stand in water while you hold a hair dryer or a heating pad.
How to Thaw Frozen Pipes Safely in 7 Steps
Work through these seven steps in order. Do not skip ahead to a stronger heat source. Gentle, steady heat is the whole method.
Step 1: Turn On the Faucet
Turn on the faucet served by the frozen pipe and leave it open. If you are not sure which faucet it is, open the faucet nearest the frozen section. If several faucets are affected, open them all.
This step matters because water pressure behind the ice is what bursts pipes. The ice itself does not burst the pipe. As water freezes, it expands and pushes against the water trapped between the ice and a closed faucet. That pressure is what cracks the pipe wall. An open faucet releases that pressure and lets melting water flow out as the ice clears. Even a small trickle is useful, because moving water is harder to freeze than still water.
Step 2: Find the Frozen Section
Now find the frozen section. Start at the open faucet and follow the pipe back toward the water supply. Feel along the pipe with your hand. The frozen part feels much colder than the rest, and you may see frost on it. Check the usual cold spots first: basement pipes along an outside wall, pipes under kitchen and bathroom sinks on exterior walls, and pipes in crawl spaces, garages, and attics. Pipe insulation helps, but it only slows freezing. A pipe with thin or missing pipe insulation in a cold spot can still freeze during a long cold snap.
Pay attention to pipe material, because it changes how the pipe behaves. A copper pipe heats evenly and thaws well with gentle heat, but it can split at a joint. A PEX pipe is flexible plastic and gives a little as ice expands, which makes it more forgiving, but it can still crack. A PVC pipe is rigid plastic and is easily damaged by high heat, so never use strong heat on it. You do not need to know your pipe material to thaw it safely. Gentle heat is safe for all three.
If you cannot find the frozen section after checking the likely places, do not guess and do not start cutting into walls. Warm the room, keep the faucets open, and call a plumber. This is also the point to decide how to thaw frozen water pipes in your home. If the frozen section is short and easy to reach, a hair dryer is the best tool. If it is long, a heating pad or warm towels may work better. If you cannot reach it at all, warming the room is the only safe homeowner option.
Step 3: Warm the Pipe With a Hair Dryer
A hair dryer is the safest and most controlled way to thaw a frozen pipe, and it is the method the American Red Cross lists first. If you searched for how to thaw frozen pipes with hair dryer heat, this is the step for you.
Set the hair dryer to high heat. Hold it a few inches away from the pipe, and move it slowly back and forth along the frozen section. Do not hold it in one spot. Constant motion spreads the heat evenly and keeps any one part of the pipe from getting too hot. Start at the faucet end and work back toward the frozen section. Warming from the faucet end lets melting water escape through the open faucet. If you start at the far end, melting water gets trapped behind the remaining ice, and the pressure can burst the pipe.
This is the frozen pipe hair dryer method in plain terms: gentle heat, constant motion, and patience. Keep the dryer moving for several minutes, then check the faucet. A trickle means the ice is starting to clear. Keep going. Do not stop at the first trickle, because ice is still in the line.
Two safety rules apply here. First, keep the hair dryer and its cord away from any water. If water starts to flow through a crack in the pipe, unplug the dryer at once and shut off the nearest water valve. Second, never use the dryer near standing water. You can unfreeze frozen pipes with a hair dryer even when the frozen section is long. It just takes longer, so work along the pipe in sections, a foot or two at a time.
Step 4: Wrap the Pipe in Towels Soaked in Hot Water
If you do not have a hair dryer, or the frozen section is in an awkward spot, towels soaked in hot water work well. The hot towels frozen pipe method is simple, and it uses items you already have at home.
Soak heavy towels in hot water, wring them out, and wrap them around the frozen section. The towels hold heat against the pipe much longer than a splash of water would. Put a bucket underneath to catch the runoff as the towels cool and drip. Replace the towels as they cool. A towel that has gone cold does nothing, so soak it again and wrap it back around the pipe. Keep the faucet open the whole time, and keep working from the faucet end back toward the frozen section.
Use hot water, not boiling water. Boiling water poured straight onto a frozen pipe can crack it, especially a PVC pipe. Warm the towels in a sink or a bucket of hot tap water. Slow, steady heat is the goal, not a sudden blast. This method is slower than a hair dryer, but it is gentle and it works on pipes in tight spaces where a dryer cannot reach.
Need Help Thawing a Frozen Pipe?
If the pipe will not thaw, or you cannot find the frozen section, do not keep guessing. Call Burst Pipe Repair Inwood at (585) 123-4567 for 24/7 emergency help. We can thaw the pipe safely, check the line for cracks, and get your water running again. A free estimate comes before any work.
Step 5: Use an Electric Heating Pad
An electric heating pad is a good choice for a short, easy-to-reach frozen section. The heating pad frozen pipe method is hands-free, which helps when the pipe is in an awkward spot and you cannot hold a dryer for an hour.
Wrap the heating pad around the frozen section and set it to medium heat. Do not use the highest setting. Medium heat is enough, and it lowers the risk of overheating one part of the pipe. Check the pad and the pipe every few minutes. Keep the faucet open, and keep watching for the first trickle of water.
Never leave a heating pad running and walk away. Stay in the room while it works. Never use a heating pad on a wet pipe or on a pipe that is already leaking. Water and an electric pad are a dangerous mix. If the pipe or the floor around it is wet, dry the area first or choose a different method. A heating pad is not the right tool for a long frozen run, because it only warms the section it touches. For a long run, move the pad along the pipe in sections, or switch to warming the room.
Step 6: Warm the Room With a Portable Space Heater
Sometimes the best way to thaw a pipe is to warm the whole room around it. A portable space heater is useful for basement pipes, pipes in a cold utility room, or pipes behind a cabinet that you cannot reach directly.
Place the heater a safe distance from the pipe and from anything that can burn. Keep it at least three feet from curtains, boxes, wood, and paper. Plug it straight into a wall outlet. Never use an extension cord for a space heater, and never leave it running while you leave the room or go to sleep.
Open the cabinet doors under sinks so warm air can reach the pipes behind them. Turn up the thermostat a few degrees. Warm air reaching the pipe from all sides thaws it slowly and evenly, which is exactly what you want. A space heater works slowly, so be patient. It is the right choice when the frozen section is long, hidden, or hard to reach.
Do not use a fuel-burning heater indoors. A kerosene or propane heater gives off carbon monoxide, a deadly gas you cannot see or smell. Only electric heat belongs inside your home for this job.
Step 7: Keep Heating Until Full Water Pressure Returns
Do not stop at the first trickle. A trickle means the ice is starting to clear, but ice is still in the line. Keep heating until full water pressure returns to the open faucet. Then keep heating for a few more minutes to make sure all the ice has melted.
This step is where many people go wrong. They see water flowing and put the dryer away, and the pipe freezes again overnight because a plug of ice is still inside. Finish the job. Full pressure, plus a few extra minutes, is the test.
Once the water runs at full pressure, turn the faucet down to a steady trickle while the cold weather lasts. Then check every other faucet in the house. One frozen pipe often means others are close behind, especially if they run through the same cold area. Watch the thawed pipe for a while. Look for drips, wet spots, or a drop in water pressure. If you see any water where it should not be, shut off the main water valve and call a plumber.
How Long Does It Take to Thaw Frozen Pipes?
How long does it take to thaw frozen pipes? For a short, exposed pipe with a hair dryer, water often starts to trickle within 30 to 60 minutes. For a longer frozen section, or a pipe inside a wall, it can take several hours. There is no fixed time, because it depends on how cold the pipe is, how long the frozen section is, where the pipe runs, and which method you use.
An exposed basement pipe thaws fastest. A pipe inside a wall takes much longer, because the heat must pass through the wall first. A small supply line thaws faster than a large main line, because there is less ice inside it. A hair dryer aimed at the pipe works faster than warming the whole room. Do not rush the job because you are cold or in a hurry. Rapid, uneven heating is what cracks pipes. If the pipe has not thawed after a few hours of steady, gentle heat, stop and call a plumber.
What Not to Use to Thaw Frozen Pipes
Knowing what not to use to thaw frozen pipes is as important as knowing what to use. The wrong heat source can start a fire, crack the pipe, or fill your home with deadly gas.
Never use an open flame. No blowtorch, no propane torch, no candle, and no lighter. A flame heats one spot of the pipe very fast, and that sudden heat can crack the pipe or melt a soldered joint. It can also set fire to wood, insulation, or dust inside a wall before you notice.
Never use a kerosene heater, a propane heater, or a charcoal stove indoors. These fuel-burning heaters give off carbon monoxide, a gas you cannot see or smell that can kill. They also have open flames and hot surfaces that can start a fire. The American Red Cross warns against every one of these devices for thawing pipes.
Never pour boiling water directly onto a frozen pipe. Boiling water is a sudden, extreme change in temperature. It can crack a frozen pipe, and it can warp or split a PVC pipe. Hot water on towels is safe. Boiling water straight on the pipe is not. Never use a high-temperature heat gun. A heat gun is made for stripping paint, and it gets far hotter than a hair dryer. It can melt plastic pipes, scorch wood, and start a fire. Never use an electric device near standing water, because electrical shock is a serious risk.
How to Thaw a Frozen Pipe Inside a Wall
A frozen pipe inside a wall is the hardest case, because you cannot see it or touch it. Many people search for frozen pipe in wall how to thaw advice when they turn on a faucet and nothing comes out, but the pipe itself is hidden.
Start with the safe steps. Open the faucet served by that pipe and leave it open. Turn up the thermostat a few degrees. Open the cabinet doors and interior doors near that wall so warm air can reach it. Aim a hair dryer at the wall surface nearest the frozen section, moving it slowly back and forth. Place a portable space heater in the room, a safe distance from anything that can burn, and let the room warm up.
These steps work because heat moves through the wall slowly. It takes time, often several hours, and that is normal. Keep the faucet open the whole time so melting water has somewhere to go.
Do not cut into the wall yourself. You cannot see where the pipe runs, where the wires are, or whether the pipe has already split. Cutting a hole can turn a frozen pipe into a flood inside your wall. Do not drill a hole to reach the pipe, and do not use a torch on the wall to warm the pipe faster. Call a plumber if the pipe does not thaw after a few hours of warming the room, if more than one faucet has no water, or if you hear water running inside the wall. If you hear running water inside a wall, shut off the main water valve first, then call.
Signs Your Pipe Already Burst While You Thaw It
Thawing can reveal a burst that the ice was hiding. Watch for frozen pipe burst signs while you work, because the faster you act, the less water damage you will have.
Stop thawing and act at once if you see any of these signs: water spraying or gushing from a crack in the pipe; a wet spot on a wall, ceiling, or floor that grows while you heat the pipe; a bulge in the pipe that splits open, or a joint that pulls apart; a hissing sound near the pipe, which can mean water escaping under pressure; water pressure that drops suddenly at the faucet while you are thawing; or water pooling on the floor near the pipe.
If any of these happen, unplug the hair dryer or heating pad at once. Do not touch an electric device while you are standing in water. Shut off the main water valve, then keep the faucet open so the remaining water can drain. Move valuables and electronics away from the water, and mop up what you can.
Then call an emergency plumber. A burst pipe needs a professional repair, and it needs it fast. For the full list of warning signs, read our guide to the signs of a burst pipe. For the first steps after a burst, read our guide on what to do when a pipe bursts.
When to Call an Emergency Plumber
Some frozen pipes are not a homeowner job. Call an emergency plumber if any of these are true: you cannot find the frozen section; you cannot reach the frozen section safely; the pipe is inside a wall, a ceiling, or a slab, and warming the room has not worked after a few hours; more than one pipe is frozen, or the whole house has no water; you see a crack, a bulge, or a leak; the water pressure does not return after thawing; or you are not comfortable working with your plumbing.
An emergency plumber frozen pipe visit makes sense in all of these cases. A plumber can find the frozen section with professional tools, thaw it without damaging the pipe, and repair a split before it floods your home. Waiting rarely helps. A frozen pipe does not get better on its own, and a small crack becomes a large flood once the ice melts.
Many homes near Dyckman Street and Inwood Hill Park have basement pipes that run along cold exterior walls, and those pipes freeze first in a cold snap. If your home has older pipes in a cold basement or crawl space, do not wait for the freeze to fix itself. If you are unsure whether your pipe is frozen or burst, treat it as a burst until a plumber tells you otherwise. Shut off the main water valve, keep the faucet open, and call for help.
What to Do After the Pipe Thaws
Getting the water back is only half the job. Spend a little time after the thaw to make sure the pipe is sound and to keep it from freezing again.
Check every faucet in the house. Run each one and look at the flow. A faucet with low pressure may have its own frozen section. Check the thawed pipe and the pipes near it for drips. A small leak can take hours to show up, so check again later in the day and again the next morning.
Keep the heat steady. Do not turn the thermostat down at night during a cold snap. The American Red Cross advises keeping home heat at no lower than 55°F when you are away, and a steady temperature protects your pipes far better than a temperature that goes up and down.
Let a faucet drip during the coldest nights, especially a faucet served by a pipe on an exterior wall. A slow trickle keeps water moving, and moving water is much harder to freeze. Add pipe insulation to the section that froze, once it is dry and the cold snap has passed. Foam sleeves are cheap and easy to fit, and they slow freezing next time. For a full prevention plan, read our guide on how to prevent frozen pipes. If the same pipe freezes again, the problem is the cold reaching it, not bad luck.
Conclusion
Thawing a frozen pipe is simple, but it must be done gently. Open the faucet. Find the frozen section. Warm it with a hair dryer, hot towels, a heating pad, or a space heater. Start at the faucet end and work back. Keep heating until full water pressure returns. Never use an open flame, a blowtorch, or a fuel-burning heater. Watch for signs of a burst while you work, and call a plumber if you cannot find the frozen section, cannot reach it, or see any damage.
Now you know how to thaw frozen pipes the safe way. Act early, work slowly, and keep your home dry this winter.
Frequently Asked Questions
Can I thaw frozen pipes with a hair dryer?
Yes. A hair dryer is the safest tool for thawing a frozen pipe. Set it to high heat, hold it a few inches from the pipe, and move it slowly back and forth. Start at the faucet end and work back toward the frozen section. Keep the dryer and its cord away from any water, and keep the faucet open while you work.
How long does it take for a frozen pipe to thaw?
A short, exposed pipe often starts to trickle within 30 to 60 minutes with a hair dryer. A longer frozen section, or a pipe inside a wall, can take several hours. The time depends on the pipe size, the length of the freeze, the location, and the method you use.
Can I pour boiling water on a frozen pipe?
No. Do not pour boiling water directly onto a frozen pipe. The sudden heat can crack the pipe, and it can warp or split a PVC pipe. Use hot tap water on towels instead. The towels hold gentle heat against the pipe without the sudden shock of boiling water.
Will a frozen pipe thaw on its own?
Yes, it may thaw when the weather warms up, but waiting is risky. While the pipe is frozen, pressure builds up behind the ice, and the pipe can burst before it thaws. It is safer to thaw it yourself with gentle heat, or to call a plumber, than to wait and hope.
What should I do if my pipe bursts while I am thawing it?
Unplug any electric device at once, without standing in water. Shut off the main water valve. Keep the faucet open so the remaining water can drain. Move valuables away from the water, mop up what you can, and call an emergency plumber right away.
Can I use a space heater to thaw frozen pipes?
Yes, if you use it safely. Place the heater a safe distance from the pipe and from anything that can burn, plug it straight into a wall outlet, and never leave it running while you leave the room or go to sleep. Never use a kerosene or propane heater indoors, because it gives off carbon monoxide.
How do I know if my pipe is frozen or burst?
A frozen pipe gives you no water or only a trickle from the faucet, and you may see frost on an exposed pipe. A burst pipe gives you water where it should not be: spraying from a crack, pooling on the floor, or dripping from a ceiling. If you see water escaping, shut off the main water valve and call a plumber.
Need Emergency Help With a Frozen Pipe?
If your pipe will not thaw, if you cannot reach the frozen section, or if you see any sign of a burst, do not wait for the problem to get worse. Call Burst Pipe Repair Inwood at (585) 123-4567 for 24/7 emergency help. We can thaw the pipe safely, check the line for cracks, and get your water running again. A free estimate comes before any work.