How to Thaw a Frozen Pipe Safely

First, figure out which pipe is frozen

Work through the faucets. If only one is dead or trickling, the freeze is on that faucet's run — usually where it passes through an exterior wall, garage, crawl space or unheated basement corner. If no faucet in the house works, the freeze is at or near the main line, and that's a call-a-pro situation.

Check exposed sections for clues: frost on the pipe, a visible bulge, or a stretch that feels far colder than the rest. North-facing exterior walls are the usual suspects in Windsor — least winter sun, most wind — along with pipes near drafts, foundation vents or garage doors.

Before you apply heat: two safety checks

Check for a split first. A pipe that has already burst may not leak until the ice melts — the ice is the only plug. Look for cracks, bulges or any existing drip along the frozen run. If you find damage, or you can't see the whole frozen section (it runs inside a wall), shut off the main water before thawing, so a hidden split can't pour the moment it opens.

Never use an open flame. No propane torch, no heat gun parked in one spot, no charcoal or kerosene heater aimed at a pipe. Open flame turns a plumbing problem into a house fire — and can superheat one spot and burst the very pipe it's meant to save. Gentle, moving heat only.

The safe thaw method

1. Open the frozen faucet and leave it open. Melting water starting to run is your progress report — and a closed faucet traps pressure against the ice.
2. Start at the faucet and work back. Apply heat to the section nearest the faucet first, then move slowly toward the coldest part of the run. Thawing from the middle out can trap meltwater between two ice plugs.
3. Use gentle heat, kept moving: a hair dryer on medium, swept back and forth; a space heater aimed at the section from a safe distance; an electric heating pad wrapped around the pipe; or towels soaked in hot water, replaced as they cool.
4. Warm the room, too. Open the cabinet doors under the sink and raise the thermostat a few degrees — it speeds everything up.
5. Keep going until full pressure returns — not just a trickle. A partial thaw leaves a plug that re-freezes faster than the first one.

How long does it take? Anywhere from half an hour for a short exposed section to several hours for a long run or a freeze inside a wall.

Stop and call if you see any of these

• Water appearing anywhere — a drip, a stain spreading on drywall, a puddle — as things thaw. The pipe has split; shut off the main and call.
• The freeze is inside a wall or ceiling and gentle room heat isn't reaching it. Cutting access and thawing safely is pro work.
• No water anywhere in the house, which points to the main line or the service line.
• You've worked a reasonable stretch — a couple of hours — with no progress. The blockage may be longer, or elsewhere, than it looks.
• The same pipe freezes every cold snap. That's not bad luck; it's insulation, routing or a draft problem that needs a permanent fix before the next snap.

Keep it from happening again

Once the water's back, the cheap insurance: foam sleeves on exposed runs, seal the draft feeding the cold spot, disconnect hoses and drain hose bibbs before freeze season, and drip a faucet on the coldest nights. For the full routine — including what to do when you travel or the power fails — see our frozen-pipe prevention guide. If the vulnerable spots sit inside walls or hard-to-reach places, a winterization visit handles them before the next cold snap.

Common questions

Frozen pipe not budging — or already split?

Call (970) 839-0039 and you will be matched with an available local pro. Frozen and burst pipe work is the core winter call in Windsor — a pipe that's already split gets priority.

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