Frozen Well Lines and Winterizing a Well

Should I turn off the well pump if pipes are frozen?

Yes. If no water is coming out at all, shut off the pump breaker. A submersible or jet pump that keeps trying to push against an ice plug can't move any water, and the motor heats up with nowhere for that heat to go. Turn it back on once you've thawed the line and opened a faucet.

If you still get a trickle, Angi's advice is to leave that faucet open while you thaw, because moving water helps melt the rest.

Where well systems freeze

1. 1

   Cause 1: The pressure switch and its tube

   The switch reads pressure through a small nipple or tube, and that bit of pipe holds very little water. In a cold basement or well house it can freeze while the main lines are still flowing. When it does, the switch can't see the pressure drop and the pump won't start, so you get no water even though the main lines are fine. Frost on the switch tube or a switch that won't click on is the giveaway.

2. 2

   Cause 2: The line entering the house

   Angi says to check where the pipes enter the foundation and along the outside walls. Look for frost on exposed pipe, a bulge, or a crack. If the pipe runs behind a wall, look for frost or condensation on the wall itself.

3. 3

   Cause 3: The pressure tank and well house piping

   Tanks in an unheated well house or garage can freeze, especially the tee and fittings at the bottom. Pentair's manual is blunt: don't let the pump, pressure tank, piping or any other component with water in it freeze. Pentair also says freezing damage voids its warranty.

4. 4

   Cause 4: The control box and wellhead

   Above-ground parts of a submersible system have cold limits too. Franklin Electric says its control boxes should be installed between 14°F and 122°F, and that below 14°F starting torque drops and overload protection is lost. A control box on an outside wall or in an unheated pit house can fail to start the pump on a very cold morning even with no ice in the pipes.

   The well casing and pump themselves rarely freeze in a working well, since they sit below the frost line. A wellhead that sits in an old pit below grade is a different story, and our well caps page covers why those pits cause trouble.

How to thaw a frozen well line

1. Turn off the pump breaker and shut the main valve to the house.
2. Find the frozen section by following the exposed pipe and feeling for the coldest spot or looking for frost.
3. Open a faucet near the frozen section so melting water and steam have somewhere to go.
4. Warm the pipe gently. A hair dryer or heating pad on a low setting works on exposed pipe. For a bigger freeze, a space heater aimed at the area works, checked every 15 minutes. Angi says a slight freeze may thaw in about half an hour and a larger one can take a few hours.
5. For a pipe that's hard to reach, heat tape wrapped in a single layer for several hours, or hot towels swapped out as they cool, both work.
6. Once water flows, turn the pump back on and watch the pressure gauge climb to cut-out. Check every joint you heated for drips.
7. Insulate the pipe before the next cold night.

For a frozen pressure switch tube, warm the tube and switch body with a hair dryer, power off, until the switch clicks on when the breaker is restored. If it won't restart after that, see low-pressure cutoff switch: how to reset it, since some switches lock out when pressure falls too low.

If the frozen pipe is underground between the well and the house, or inside a finished wall, stop. Thawing a buried line takes equipment most homeowners don't have.

When to call a pro, and what it costs

Call a well contractor or plumber when the frozen section is buried or behind a finished wall, when a pipe or fitting has split, when the pump won't start after the lines are thawed, or when the pressure switch or tank cracked. A pump that ran against an ice plug for a while may have damage of its own; our page on signs your well pump is going bad covers what to watch for.

HomeGuide's 2026 figures for parts that commonly fail after a freeze, parts and labor included:

How to winterize a well and keep it from freezing

Most of this is a weekend of insulation and a little wiring.

• Insulate every exposed pipe between the wellhead and the house, plus any pipe behind walls you can get to.
• Put an insulated well box or enclosure over an above-ground wellhead and the piping beside it.
• Insulate and seal the well house, crawl space or basement where the tank and switch live. Drafts do more damage than raw cold, so seal vents and gaps on the cold side.
• Add heat tape or heat cable to the most exposed runs and the switch tube. Use cable rated for water pipes, follow its instructions, and plug it into a GFCI outlet.
• Keep a small heat source in a well house, set to keep the space above freezing. A thermostatically controlled heater is safer than a heat lamp left burning.
• In a cold snap, leave a light trickle running at a faucet.
• Shade and shelter the control box if it's outside, and don't let it sit where it will drop below its rated minimum.

Winterizing a house you're leaving empty

For a cabin or a house you're shutting down for the winter, the safe approach is to drain it rather than heat it. Turn off the pump, drain the pressure tank, open every faucet, drain the water heater, and blow out or drain the lines. Have a well contractor handle the pump side if you have a jet pump, since its casing and suction line hold water above ground.