When a January cold snap pushes temperatures below zero in Idaho Falls, Rexburg, or Island Park, frozen pipes stop being a theoretical risk and become a Tuesday-morning surprise. You turn the faucet and nothing comes out — or worse, you hear water running somewhere it shouldn't be. What you do in the next thirty minutes matters more than almost anything a plumber does later, because a frozen pipe that thaws uncontrolled can dump hundreds of gallons into a wall or crawl space.

This guide walks you through confirming the freeze, protecting your home, thawing safely, and knowing when to stop DIY-ing and request a plumber.

Is It Actually Frozen? Ruling Out an Airlock or Supply Problem

Not every dry faucet means ice. Before you crawl under the house with a hair dryer, spend two minutes narrowing it down:

  • Check other fixtures. If every faucet in the house is dead, the problem may be at the main supply, the meter, or — on rural properties around Iona or Shelley — the well pump or pressure tank. A freeze usually knocks out one fixture or one side of the house first.
  • Hot side vs. cold side. If only the hot water is out, suspect the line feeding from your water heater rather than the main. If only cold is out at one sink, the freeze is likely in that branch line.
  • Listen for sputtering. An airlock (trapped air after recent plumbing work or a well pressure issue) tends to sputter and spit before flow returns. A frozen pipe is silent — you get a trickle or nothing at all.
  • Feel the pipe. Where lines are accessible, a frozen section is noticeably colder than the pipe around it, and may have frost on it or a slight bulge.

If the whole neighborhood lost water, call your city utility or water district before doing anything else. If it's just your house, keep reading.

First Moves: Protect the House Before You Thaw Anything

1. Find your main shutoff — now, not later

Ice expands with enough force to split copper and crack PEX fittings. The dangerous moment isn't while the pipe is frozen; it's when it thaws and pressurized water finds the crack. Locate your main shutoff valve (usually where the supply enters the house — often the basement, crawl space, or a utility room in East Idaho homes) so you can kill the water in seconds if a leak appears. If the pipe is already split or you can see water, shut the main off immediately.

2. Open the affected faucet

Open the faucet served by the frozen line, plus one more downstream if you can. This relieves pressure trapped between the ice blockage and the fixture, and gives melting water somewhere to go. Even a trickle starting up is a good sign — moving water helps thaw the rest.

3. Warm the space, not just the pipe

Open cabinet doors under sinks on exterior walls, and get warm household air circulating toward the frozen area. If the freeze is in a crawl space, a safe space heater positioned well away from insulation and debris can raise the ambient temperature while you work.

Safe Thawing Methods (and the Ones That Burn Houses Down)

Do use:

  • A hair dryer. The workhorse. Start at the faucet end and work back toward the frozen section so meltwater can escape. Keep it moving.
  • Electric heat tape or heat cable. Wrapped along the frozen run per the manufacturer's instructions, it thaws gradually and can stay in place as prevention afterward.
  • Towels soaked in hot water. Wrapped around the pipe and refreshed as they cool — slow but safe for tight spots.
  • A space heater in the room or crawl space, kept clear of anything flammable and never left unattended.

Never use:

  • An open flame. No propane torch, no heat gun on high against wood framing. Crawl spaces are full of dry joists, insulation, and dust — a torch is how a frozen pipe becomes a house fire. Rapid flame heating can also boil water inside the pipe and burst it.
  • Anything electric in standing water. If the crawl space is already wet, cut power to the area before working in it.

When It's an Emergency

Some situations shouldn't wait for a slow DIY thaw. Treat it as an emergency and request emergency plumbing help if:

  • A pipe has already burst or you see active leaking — shut off the main and get help.
  • The frozen section is inside a wall or ceiling where you can't reach it or watch it thaw.
  • You can't locate or turn your main shutoff valve.
  • The freeze involves your water heater, well supply line, or main service line.
  • You've been thawing for a couple of hours with no progress — the blockage may be longer or less accessible than you think.

Emergency requests are prioritized, and a licensed local plumber can thaw lines with proper equipment, pressure-test the run, and repair any splits before they flood a finished basement.

Why East Idaho Homes Freeze Where They Do

The usual suspects here are predictable. Crawl spaces are common across the Snake River Plain, and any water line running through an unheated, poorly sealed crawl space is exposed to outdoor-adjacent temperatures for months. Foundation vents left open into winter make it worse. Hose bibs are the other classic failure: a garden hose left connected traps water in the sillcock, which freezes and splits the pipe just inside the wall — you often don't discover it until you use the spigot the next spring and water pours into the basement.

Older homes in central Idaho Falls, Pocatello, and Blackfoot often have supply lines routed along exterior walls or through minimally insulated rim joists, while newer construction in Ammon and Rexburg usually fares better — but even new homes freeze when a cold snap coincides with a power outage or a thermostat set too low during a trip.

After the Thaw: Prevent the Repeat

Once water is flowing, inspect every inch of the affected run you can reach for drips, bulges, or frost-cracked fittings, and watch it under pressure for a few minutes. Then fix the conditions that caused the freeze: insulate the run, add heat tape, seal crawl space vents and air leaks, and disconnect hoses before the first hard freeze. Our full East Idaho winterization guide covers the complete checklist, from irrigation blowouts to vacation prep.

And if the same pipe freezes every winter, that's a design problem, not bad luck — a plumber can reroute the line or add permanent freeze protection. Tell us your city and we'll connect you through our East Idaho service areas.