Winterize your well pump by draining water from exposed pipes, insulating above-ground components, and shutting off the system if you'll leave the house empty

Winterizing a well pump means removing water that can freeze and crack pipes, wrapping exposed equipment against cold, and preparing the system to sit idle if needed. The work takes a few hours and costs $50 to $150 in materials—far less than replacing burst pipes or a damaged pump. Most homeowners can do this themselves if they follow the steps in order and know where their pump, pressure tank, and shutoff valve are located.

The timing matters: winterize when nighttime temperatures drop below 40°F and stay there, usually in October or November depending on your region. If you wait until a hard freeze is forecast, you may not have time to finish before the cold arrives.

Key Takeaways

  • Drain all water from exposed pipes, the pressure tank, and the pump itself before freezing weather arrives, because standing water expands when it freezes and splits pipes.
  • Wrap the pump, pressure tank, and any above-ground pipes with foam insulation or heat tape rated for outdoor use, securing it tightly so wind does not dislodge it.
  • Close the main shutoff valve between the well and the house, then open the lowest faucet inside to release pressure and prevent water from backing up into the system.
  • If you plan to leave the house empty for the winter, shut off power to the pump at the breaker and drain the pressure tank completely to prevent damage from frozen water.
  • Check that your pump has a check valve installed—it prevents water from flowing backward into the well when the system is off, which protects the pump from freezing damage.

Locate your pump, pressure tank, and main shutoff valve

Before you start draining or wrapping anything, find these three components and trace the pipes between them. The pump itself is usually in a basement, crawlspace, or buried in a concrete pad outside. The pressure tank—a metal cylinder 20 to 80 gallons in size—sits near the pump or inside the house. The main shutoff valve is the ball valve or gate valve on the pipe that leaves the pump and heads toward the house.

Write down the locations and take a photo of each one. If you cannot find the shutoff valve, ask your well contractor or a plumber to show you where it is; you cannot winterize safely without knowing how to stop water flow. Check whether your pump has a check valve installed on the discharge line—it looks like a small cylinder with one inlet and one outlet. If you do not see one, mention it to a contractor; a missing check valve is a common reason pumps freeze.

Drain water from the pressure tank and all exposed pipes

Turn off power to the pump at the breaker. Then close the main shutoff valve between the pump and the house. Open the lowest faucet inside the house—usually a basement sink or outdoor spigot—and leave it open until water stops flowing. This releases pressure in the system and lets air into the pipes so water drains completely instead of pooling.

Next, drain the pressure tank itself. Most tanks have a drain valve at the bottom; attach a garden hose and open it fully, directing water away from the foundation. Let it run until no more water comes out. If your tank has no drain valve, you may need a plumber to drain it, or you can skip this step if the tank is inside a heated space—but if it is outside or in an unheated building, draining it is essential.

Open any drain plugs on the pump housing or on pipes near the pump. Some pumps have a small plug on the side; turn it counterclockwise by hand or with a wrench and let water drip into a bucket. Leave all drain valves and plugs open so air can circulate and any remaining water can evaporate. Close them again in spring before you restart the system.

Insulate the pump, pressure tank, and above-ground pipes

Wrap the pump and pressure tank with foam pipe insulation or fiberglass blanket rated for outdoor use. Foam pipe insulation comes in tubes that split lengthwise; slide them over pipes and seal the seams with duct tape or foam tape. For the tank itself, wrap it with a 2- to 4-inch-thick fiberglass blanket, securing it with rope or zip ties so wind cannot tear it loose. Do not use plastic sheeting alone—it traps moisture and can make freezing worse.

Wrap any exposed pipes between the pump and the house, paying special attention to pipes that run along the outside of the building or through unheated spaces. Insulation works best when it is at least 1 inch thick and covers the entire length of the pipe. If pipes are in a very cold location—such as an unheated garage or crawlspace—consider adding heat tape, which is an electric cable that wraps around the pipe and warms it when temperatures drop. Heat tape uses very little power and can prevent freezing in the coldest climates.

Check your work by running your hand over the insulation; it should feel snug with no gaps where cold air can reach the pipe or equipment underneath. Loose insulation is almost useless.

Shut off power if you are leaving the house empty

If you plan to be away from the house for more than a few days during winter, turn off power to the pump at the breaker and leave it off. A pump that runs while the house is empty and no one is using water can cycle on and off repeatedly, and if a pipe has a small crack, the pump may run continuously trying to maintain pressure—wasting energy and potentially damaging the motor.

Before you leave, make sure the pressure tank is completely drained (see the section above). If you return and want to restart the system, turn the power back on at the breaker and open the main shutoff valve. The pump will run and refill the pressure tank; listen for the motor to stop, which means the tank is full and pressure has reached the cutoff point. If the pump runs for more than a few minutes without stopping, turn it off and call a plumber—there may be a leak.

Test your system in early spring before you need water

In March or April, before you rely on the well for daily use, test it to make sure winterization did not cause damage. Turn the power back on at the breaker and open the main shutoff valve slowly. Listen for the pump to start and run until pressure builds. Open a faucet and let water run for a minute; it may be cloudy or discolored at first, which is normal. If water runs clear and the pump shuts off normally, you are ready for spring.

If the pump does not start, the power is off at the breaker, or if water does not flow, do not force it. Turn everything off and call a well contractor. Trying to restart a frozen or damaged pump can cause more harm.

Common mistakes that damage well pumps in winter

The most common error is leaving water in the pressure tank or in exposed pipes. Even a small amount of standing water will freeze, expand, and crack the tank or split the pipe. If you drain the tank but forget to open the lowest faucet inside, water will back up into the system and freeze there instead. Always open that faucet and leave it open until water stops flowing.

Another mistake is using insulation that is too thin or leaving gaps. Foam pipe insulation that is less than 1 inch thick will not stop freezing in very cold climates. Wrapping the tank but leaving the drain valve exposed is also ineffective. Take time to cover every part of the pump and tank, and seal all seams with tape.

A third error is turning off power but not draining the tank first. If the tank still holds water and the pump is off, that water will freeze solid and may crack the tank. Always drain before you shut off power.

Frequently Asked Questions

Do I need to winterize if my pump is inside a heated basement?

If the pump, pressure tank, and all pipes are inside a space that stays above 50°F all winter, you do not need to winterize. However, if any pipe runs through an unheated space—such as a crawlspace, garage, or exterior wall—wrap those sections with insulation. Even a basement pump can have an exposed pipe that freezes.

What if I cannot find the drain valve on my pressure tank?

Not all tanks have a drain valve on the outside. If yours does not, you can hire a plumber to drain it, or you can leave it full if the tank is inside a heated space. If the tank is outside or in an unheated building, draining it is important. A plumber can add a drain valve if you plan to winterize regularly.

Can I use regular plastic sheeting to wrap the pump instead of foam insulation?

Plastic sheeting alone will not protect against freezing and can trap moisture, making the problem worse. Use foam pipe insulation, fiberglass blanket, or heat tape rated for outdoor use. Plastic can be a layer on top to keep rain off, but it must cover foam or fiberglass underneath.

How long does winterization take?

Most homeowners finish in two to four hours, depending on how many pipes are exposed and how far the pump is from the house. Draining takes 30 to 45 minutes. Wrapping the pump, tank, and pipes takes another one to three hours. If you hire a plumber, expect to pay $200 to $400 for the full job.

What should I do if a pipe bursts during winter?

Turn off power to the pump at the breaker when ready. Close the main shutoff valve if you can reach it. Do not try to thaw the pipe with a heat gun or torch—you risk making the crack worse. Call a plumber. In the meantime, you can melt snow or ice and use it for flushing toilets, but do not drink or cook with it.