Frozen Pipes: How to Prevent Them and What to Do If It Happens

Frozen pipes are one of the most expensive winter plumbing problems. The pipe itself is not always the issue — it is the thaw. Water expands as it freezes, and when it thaws quickly, the pressure spike can split copper and PEX alike.

Why pipes freeze

Pipes freeze in areas with poor insulation or no heat: exterior walls, crawl spaces, garages, and cabinets on outside walls. Supply lines to outdoor hose bibs are the most common failure point.

Prevention

Keep the heat on. If you leave for more than a day in winter, keep the thermostat at 55°F minimum. Pipes in unheated spaces do not care what your living room temperature is.

Open cabinet doors under sinks on exterior walls. This lets warm air circulate around the pipes.

Let faucets drip. Moving water is harder to freeze. A slow drip on the cold side of faucets served by exposed pipes costs almost nothing and prevents a lot of damage.

Insulate exposed pipes. Foam pipe insulation is inexpensive and takes an afternoon to install. Pipes in the garage, crawl space, or attic are the priority.

Disconnect and drain garden hoses. Water left in the hose freezes back into the bib and splits it.

If a pipe freezes

Do not use an open flame. Torches and heat guns cause house fires and can damage pipe. Use a hair dryer, an electric heating pad, or warm towels.

Start from the faucet end and work back. This lets water escape as it thaws and reduces pressure buildup.

Turn off the water supply before you start. If the pipe has already cracked, you want to be ready to stop the flow immediately.

Call a plumber if you cannot locate the frozen section. Pipes inside walls and under slabs need professional equipment to thaw safely.

The difference between a $200 repair and a $5,000 insurance claim is usually whether the pipe was found before it burst.