How to Thaw Frozen Pipes Safely
Updated September 18, 2026
Can I do this myself?
DIY with precautions
Yes, you can safely thaw an exposed frozen pipe yourself with gentle heat like a hair dryer or warm towels. Never use an open flame, and shut off the main water valve immediately if you find a split.
When temperatures drop well below freezing, water in exposed or poorly insulated pipes can freeze. The first sign is usually a faucet that gives only a trickle or nothing at all, often on a cold morning. Pipes in unheated spaces (garages, crawlspaces, basements, attics, outside walls and under kitchen sinks on exterior walls) are most at risk.
A frozen pipe is a warning, not yet a disaster. Ice expands as it forms, building pressure between the ice and the closed faucet, which is why pipes often split. The split may not leak until the ice melts, so thawing is when a burst often becomes obvious. Knowing where your main water shut-off valve is before you start is essential.
Thawing an accessible pipe is a safe DIY job if you use gentle heat, work from the faucet back toward the frozen section, and keep electrical devices away from water. Never use an open flame, a propane torch or a gas heater: they can ignite building materials, damage pipes and are a serious fire risk.
Also searched as: frozen pipes · how to thaw frozen pipes · no water coming out of tap in winter · pipes frozen what to do · how to tell if pipes are frozen · thaw frozen pipe with hair dryer
Signs of the problem
- No water, or only a trickle, from one or more faucets in cold weather
- Frost or ice visible on an exposed pipe
- A pipe that feels much colder than others or bulges slightly
- The toilet won’t refill after flushing
- Unusual smells from drains, as air can’t move through a frozen line
- Water stains or dampness near a pipe, which can signal a split
Common causes
Pipes in unheated spaces
Most commonPipes running through garages, crawlspaces, attics, basements and exterior walls are exposed to outdoor temperatures and freeze first, especially during long cold snaps.
Poor or missing insulation
Most commonPipes without foam sleeves, or in walls with gaps in insulation, lose heat quickly. Drafts from vents, gaps around pipes or a door left open can freeze a pipe in hours.
Heating turned down or off
SometimesSetting the heating very low while away, or a heating failure, lets the whole building cool. Cabinets closed over pipes on exterior walls also keep warm air away.
Outdoor hoses or supply lines left connected
SometimesA garden hose left on an outdoor faucet traps water, which can freeze back into the pipe inside the wall. Irrigation and pool supply lines are also vulnerable.
Safety first: before you start
- Critical:Never use an open flame, propane torch, blowtorch, kerosene or gas heater to thaw pipes. This is a major cause of house fires.
- Critical:Find your main water shut-off valve before you start, so you can shut the water off instantly if a pipe splits.
- Critical:Keep hair dryers, heating pads and space heaters away from standing water, and don’t use them if you are standing in water. Plug into a GFCI-protected outlet if you can.
- Don’t leave a space heater unattended, and keep it well away from walls, insulation, curtains and anything that can burn.
- If water is leaking near electrical outlets, wiring or light fixtures, shut off power to that area at the breaker or fuse box, but only if you can reach it while standing on dry ground.
Tools & materials
Tools
- Hair dryer or heat gun on a low setting (kept moving)
- Electric heating pad
- Portable space heater (with tip-over and overheat protection)
- Flashlight
- Bucket and towels
Materials
- Towels or rags soaked in hot water
- Foam pipe insulation sleeves (for prevention afterwards)
- Pipe repair clamp or repair tape (temporary stopgap only)
Step-by-step fix
- 1
Find the main shut-off valve
Locate the main water valve before you apply any heat. It is often where the water line enters the building: in a basement, utility room, under the kitchen sink, near the water meter or outside. Make sure it turns.
Tip: Hang a tag on the main valve once you find it. In an emergency, you won’t want to search for it.
- 2
Open the affected faucet
Open the faucet the frozen pipe feeds (both hot and cold if it is a mixer). This relieves pressure and lets water flow out as the ice melts, which helps melt the rest faster.
- 3
Find the frozen section
Trace the pipe from the faucet back toward where it comes from, focusing on sections in cold areas or on exterior walls. Look for frost, and feel for the coldest spot. Open cabinet doors under sinks to let warm air in.
- 4
Check for splits before thawing
Inspect the pipe carefully with a flashlight for cracks, bulges or splits. If you find one, shut off the main water valve before you thaw it, because it will leak as soon as the ice melts.
Warning: If a pipe has split, thawing it with the water on can flood the area quickly. Shut the main first and call a plumber.
- 5
Apply gentle heat, starting near the faucet
Warm the pipe starting at the faucet end and working back toward the frozen section, so melting water has somewhere to escape. Use a hair dryer moved back and forth along the pipe, wrap it in an electric heating pad, or wrap towels soaked in hot water around it and replace them as they cool.
Warning: Never use an open flame or torch. Keep the hair dryer moving and don’t aim it at plastic pipe from close range for long; too much heat can soften it.
- 6
Warm the space if the pipe is hard to reach
For pipes in a cold room or under a cabinet, a space heater set at a safe distance can raise the air temperature. Keep it well away from anything flammable, on a stable surface, and never leave it unattended.
- 7
Keep going until full pressure returns
Keep heating until water flows at normal pressure. Then check every other faucet in the house: if one pipe froze, others may have too.
- 8
Inspect for leaks after thawing
Once water is flowing, check the pipe you thawed and nearby joints for drips, especially over the next few hours. Look for damp patches on walls or ceilings near the pipe’s route.
- 9
If a pipe leaks, shut off and patch temporarily
If you find a leak, shut off the main water valve immediately. A pipe repair clamp or repair tape can slow a small leak as a temporary fix until a plumber can replace the section. See the burst pipe guide for next steps.
Stuck on a step?
Point your camera at it and a Fixwise expert voice will guide you through it, safely.
How to check it's fixed
- Normal water flow and pressure at the faucet that was frozen
- All other faucets and toilets in the house work normally
- No drips or damp patches along the pipe several hours after thawing
- No new stains on walls or ceilings near the pipe’s route
When to stop and call a professional
- The frozen section is inside a wall, ceiling or floor you can’t reach
- You find a split, crack or bulge in the pipe
- Several pipes are frozen, or you can’t locate the frozen section
- Water is leaking near electrical wiring, outlets or fixtures
- The pipe hasn’t thawed after a few hours of gentle heating
- You can’t find or close the main water shut-off valve
How to prevent it
- Insulate exposed pipes in unheated areas with foam sleeves, and seal drafts near pipes.
- During hard freezes, keep the heating on (even when away) and open cabinet doors on exterior walls.
- Let a faucet on a vulnerable line drip slowly during extreme cold to keep water moving.
- Disconnect garden hoses and shut off and drain outdoor faucets before winter.
- Consider thermostatically controlled heat cable, installed per its instructions, on pipes that freeze repeatedly.
Frequently asked questions
How do I know if my pipes are frozen?
The clearest sign is no water, or only a trickle, from a faucet during very cold weather while other fixtures work. You may also see frost on exposed pipes or notice a toilet that won’t refill.
Can frozen pipes thaw on their own?
Yes, as temperatures rise, but slowly, and the risk of a split pipe remains while they are frozen. Gentle heating is safer than waiting, because you can watch for leaks as the ice melts.
Why can’t I use a torch to thaw pipes?
Open flames can ignite wood, insulation and dust in walls and floors, and can overheat pipes and joints. Torches are a well-known cause of house fires during cold snaps. Use a hair dryer, heating pad or warm towels instead.
Should I turn off the water if my pipes are frozen?
Not always, but know where the main valve is and be ready. If you see a split or crack, or water starts leaking as you thaw, shut the main valve immediately.
Will a frozen pipe always burst?
No. Many frozen pipes thaw without damage. But ice builds pressure in the pipe, and splits are common, especially in older or thinner pipes. That is why you should check for leaks carefully during and after thawing.
This guide is general information, not professional advice. Homes differ, so follow your product manuals and local codes. If anything looks different from what's described, or you feel unsure, stop and call a qualified professional. In an emergency, leave the area and call your local emergency number.
Related guides
Burst pipe
EmergencyThis is an emergency, not a DIY repair. Your job is to stop the water, stay safe from electricity and limit damage; the pipe itself should be repaired by a plumber.
Leaking outdoor faucet
Safe to DIYYes, this is a straightforward DIY repair once the water supply to the faucet is shut off. The main risk is water damage if a frost-free faucet has split inside the wall.
Low faucet pressure
Safe to DIYYes, fixing low pressure at a single faucet is safe and usually takes minutes. If the pressure is low everywhere in the house, the cause is likely outside your fixtures and needs a plumber or your water utility.
Ceiling water stain
DIY with precautionsCovering a dry, stable stain is a safe DIY job. Finding the leak is the real work, and a sagging, bulging or dripping ceiling is a stop sign: keep people away and get help, because wet ceiling boards can collapse.