Pipes Are Frozen — Who Do I Call?

Do these three things now, in this order

1. Shut off the main water valve. Clockwise until it stops. A pipe can already be split under the ice and held shut by it — you find out at the moment it thaws. With the main off, that discovery is a wet patch. With the main on, it is a flood while you are standing in another room with a hair dryer.
2. Open the faucet that frozen line feeds. Leave it open. Melting ice needs an exit, and the open tap takes away the pressure that actually bursts pipes.
3. Check every other fixture in the house. Hot and cold, a few seconds each, and note which ones give nothing. If one line froze, others on the same run are sitting in the same cold air — and the map of which taps are dead is how you find the blockage.

Then leave the heat on and the interior doors open. Everything below is done with the water off.

Finding the frozen section

The dead faucet tells you the run. The cold tells you the spot.

Water freezes where a pipe passes through space that isn’t heated, so follow that run and look at exactly those places: exterior walls, unheated crawl spaces, garages, attics, north-facing walls that never see winter sun, the rim joist above a basement wall, the cabinet under a kitchen sink on an outside wall, and the line out to a hose bibb. A pipe running through the middle of a heated house almost never freezes. One crossing an uninsulated bay for four feet does it every hard winter.

What you are looking for when you get there: frost or heavy condensation on the pipe, a section noticeably colder than the pipe either side of it, ice visible at a fitting, or a slight bulge. Run a hand along it — the frozen stretch is unmistakable once you touch it.

Two shortcuts worth knowing:

• Nothing works anywhere in the house. The freeze is near where the service line comes in, or at the meter. That is the one case where the water utility’s emergency line comes before the plumber.
• Only one branch is dead. You have narrowed it to that branch already. Walk it from the fixture backwards until it leaves heated space.

And the case with no shortcut: the run disappears into a finished wall, a sealed ceiling, or under a slab. That is not a failure of searching. That is the call-a-plumber case, below.

Thawing it without starting a fire

Keep the faucet open the whole time. Then work from the faucet end back toward the blockage — never the reverse. Melting ice produces water and steam that need somewhere to go; heat the middle of a plug first and you can trap meltwater between two walls of ice and split the pipe yourself.

What to use:

• A hair dryer, moving constantly along the pipe rather than parked on one spot.
• A heat lamp or an incandescent work light set back from the pipe, useful for a crawl space or a cabinet where you can leave it running while you watch.
• Towels soaked in hot water, wrapped around the section and re-soaked as they cool. Slow, safe, and works on pipes you can only just reach.
• An electric space heater at a distance, aimed at the wall or the open cabinet from several feet away. Not pressed against anything, not under a sink full of cleaning bottles, and not left running while you go to bed.
• Heat tape or heat cable sold for water pipes, installed the way the instructions say.

For a pipe behind drywall, you are heating the room and waiting. Raise the thermostat, open the cabinet or closet doors, put a space heater a safe distance from that wall, and give it hours rather than minutes.

Never an open flame. No propane torch, no blowtorch, no kerosene or charcoal heater. This is the single most reliable way to turn a $100 problem into a house fire: torches ignite framing and old insulation inside the wall cavity where you cannot see it, they melt solder joints and dump water into whatever they just set alight, and they can boil water inside a closed section fast enough to rupture it. Unvented kerosene and propane burners add carbon monoxide to a house you have sealed up against the cold. A hair dryer is genuinely the professional answer here.

When to stop and call a plumber

Stop and call if any of these are true:

• You can’t find it. Heating pipe at random is how people spend a night warming the wrong wall.
• You can’t reach it — inside a finished wall, above a sealed ceiling, under a slab, or in a crawl space you cannot get into. Some plumbers thaw metal pipe with a machine that passes current through the run itself, which reaches sections you never could. It does not work on PEX or plastic, so say what your pipes are when you book.
• No flow returns after a decent effort. Either the ice is somewhere other than where you think, or the pipe has already failed and the ice is the only thing holding it shut.
• You can see a bulge, a split, or a deformed section. Call before you thaw. Applying heat to that is just choosing when the water arrives.
• Water appears while you are working. Main stays off, heat sources off, plumber now.

The money makes the decision easy. Fixr lists a flat-rate thaw at $100, plumber hourly rates at $75 to $150 with a national average of $90, and an initial service call at $50 to $150 for a journeyman or $150 to $300 for a master plumber. Against that, a burst pipe repair runs $200 to $1,000 with a national average of $500 — $150 to $500 in a wall or kitchen, and $500 to $4,500 under a slab, where frozen pipe repairs of every kind span $150 to $5,000.

After-hours pricing is real, though: Fixr puts the emergency rate at $150 an hour as standard, plus a $50 to $200 transportation fee and a $200 to $300 flat call-out. If the water is off, the house is warm, and nothing is leaking, morning is usually fine. If the house is cold and getting colder, it isn’t — you are paying the premium to avoid the repair.

Right now this is one trade and one bill. If it bursts, it becomes four — plumber, mitigation crew, rebuild contractor, insurer — and who actually does what is worth reading before you are making those calls in a wet hallway.

If the pipes froze because the heat died

Then the frozen pipe is a symptom and you have the wrong emergency in mind. A house with no heat in a hard freeze does not produce one frozen pipe; it produces a run at a time, over hours, in whatever order the cold reaches them. Thawing one line while the furnace is still dead is bailing.

Call the HVAC technician first, then deal with the pipe — and while you wait, run through the six checks that solve a surprising share of no-heat calls, because a dead thermostat battery and a tripped furnace switch both cost nothing to rule out and both end this in five minutes.

Keep cabinet doors under sinks open, close off rooms nobody is in, and let taps drip on the runs that still work. If the house is genuinely dropping toward freezing and the repair is hours away, shutting the main and draining the system is a better night than the alternative.

If you rent, tell the landlord in writing before you book anyone. Heat and running water are habitability requirements almost everywhere, usually with a defined response window measured in hours, and most leases require written notice and a chance to repair before you can charge anything back. Call your own plumber first and the bill is very likely yours. The escalation ladder, with the deadlines and the retaliation protections, is the thing to have open while you write that message.

When it bursts

If you hear it, or the wall goes dark, or water starts coming through a ceiling: the main is already off, which was the point of step one. From there it stops being this page’s problem — a burst pipe has its own sequence, starting with photographs before you mop and ending with the order in which the plumber, the restoration crew, and the adjuster get called.

Freeze bursts are the textbook covered loss, provided the property was heated. Photograph the thermostat and the room temperature now, before anything happens — unheated and unattended homes are the standard denial route, and the picture costs you nothing. Whether to file at all is a different question from whether it is covered, and running the deductible math before you call the claims line is worth the ten minutes.

Preventing the next one

All of this is free or nearly free, and it is the reason some houses on a street get through a cold snap and others don’t.

• Let faucets drip in a hard freeze. The Insurance Information Institute’s advice is to open hot and cold faucets enough to let them drip slowly, and to keep the house heated to a minimum of 65 degrees. Moving water is much harder to freeze, and a dripping tap keeps pressure from building behind a plug that forms anyway.
• Open cabinet doors under sinks on exterior walls so heated room air reaches the pipes. This is the single most common freeze point in an occupied house.
• Disconnect garden hoses before winter, shut the interior valve feeding each hose bibb, and drain the line. A hose left attached holds water against the bibb and freezes the line back into the wall.
• Insulate the runs that pass through cold space — crawl space, garage, attic, rim joist. Foam sleeves cost a few dollars a length and go on in an afternoon.
• Find your main shut-off valve now, and turn it to confirm it actually closes. A valve nobody has touched in fifteen years is often seized, and the moment you need it is the wrong moment to learn that.
• Leaving the house in winter? Don’t set the thermostat below 55, ask someone to check on it, and if it will be empty for a long stretch, have the system drained properly.