What you need to know before you start

Replacing a submersible well pump is a job most homeowners can do themselves if the pump is shallow enough — typically 25 feet or less. The basic process involves pulling the pump and pressure tank out of the well, disconnecting the electrical and water lines, installing the new pump, and lowering it back down. If your well is deeper than 25 feet, the weight and complexity usually make it worth hiring a licensed well contractor instead.

Before you begin, turn off the power at the breaker and drain the pressure tank completely. You will need a pipe wrench, a submersible pump puller or rope and pulley system, electrical tape, and a new pump matched to your well's depth and flow rate. Check your old pump's nameplate for the horsepower, voltage, and depth rating — your replacement should match or exceed these specs.

Key Takeaways

  • Shallow wells (under 25 feet) are usually manageable for a homeowner; deeper wells typically require a contractor because of the weight and risk of dropping the pump.
  • You must turn off power at the breaker and drain the pressure tank before you touch anything in the well.
  • The pump sits at the bottom of the well on a drop pipe; you pull it out by hand or with a rope and pulley, then disconnect the electrical cable and water line.
  • The new pump must match your old pump's voltage, horsepower, and depth rating, or it will not work correctly or may fail early.
  • Lowering the new pump back into the well requires care — dropping it can crack the casing and contaminate your water supply.

Gather your tools and materials

You will need a pipe wrench (adjustable or fixed), a submersible pump puller if you have one, or a rope and pulley system if you do not. A pump puller is a metal frame that hooks under the pump head and lets you pull straight up without twisting the drop pipe. If you do not own one, you can rent one from a tool rental shop for about $20 to $40 per day, or you can use a rope looped around the pump head and a pulley attached to a beam above the well.

Gather electrical tape, a voltage tester, a bucket for draining water, and a new submersible pump. Before you buy the pump, write down the horsepower, voltage (usually 240V or 120V), and depth rating from your old pump's nameplate. The new pump must match these specs. You will also need a new drop pipe if the old one is corroded or cracked, and new electrical cable if the old one is damaged.

Have a helper on hand if possible. Pulling a pump out of a well is a two-person job — one person operates the puller or rope while the other guides the pump and watches for snags.

Turn off power and drain the system

Locate your well pump breaker in your electrical panel and switch it to the off position. Use a voltage tester on the pump's electrical cable to confirm the power is actually off — do not rely on the breaker alone. A voltage tester is inexpensive and can prevent a serious shock.

Next, drain the pressure tank. Open the drain valve at the bottom of the tank and let the water run into a bucket until nothing comes out. This step is critical because a pressurized tank can spray water and cause injury when you disconnect the lines. After the tank is empty, open a faucet in the house to release any remaining pressure in the pipes.

Pull the pump out of the well

Remove the well cap or sanitary seal at the top of the well. If you have a submersible pump puller, position it over the well opening and hook it under the pump head. If you are using a rope and pulley, loop the rope around the pump head and thread it through a pulley attached to a sturdy beam or tripod above the well.

Begin pulling slowly and steadily. The pump will be heavy — a typical 1-horsepower pump weighs 40 to 60 pounds — and the drop pipe adds more weight. Pull straight up without twisting. If the pump sticks, do not force it; stop, wiggle it gently side to side, and try again. Forcing a stuck pump can bend the drop pipe or break the electrical cable.

As the pump rises, have your helper guide the drop pipe and electrical cable so they do not snag on the well casing. Once the pump clears the well opening, set it on a clean surface and let it drain into a bucket.

Disconnect the old pump

Use a pipe wrench to unscrew the drop pipe from the pump head. The connection is usually a threaded union or a straightforward threaded fitting. Turn the wrench counterclockwise and work slowly — the pipe may be stuck from mineral buildup. Once the pipe is free, cap the end with a clean rag or plastic cap to keep debris out.

Next, disconnect the electrical cable. Most submersible pumps have a waterproof connector at the top where the cable enters the pump head. Unscrew this connector by hand or with a wrench, depending on the type. Once the connector is loose, pull the cable free and set it aside. If the cable is damaged or frayed, mark it so you do not accidentally reconnect it to the new pump.

Install the new pump and reconnect everything

Before you lower the new pump into the well, screw the drop pipe onto the pump head using a pipe wrench. Tighten it firmly but do not over-tighten, which can crack the fitting. The drop pipe should be the same diameter and length as the old one — if it is not, the pump may not sit at the correct depth or may not deliver water at the right pressure.

Attach the electrical cable to the pump's connector. Make sure the connector is rated for submersible use and that the cable matches the pump's voltage. If you are unsure, check the pump's manual or call the manufacturer. Wrap the connection with electrical tape to seal it against water.

Now lower the pump slowly into the well. Have your helper guide the drop pipe and cable so they do not twist or snag. Lower the pump hand over hand if you are using a rope, or crank the puller down slowly if you are using a mechanical puller. Stop when the pump reaches the bottom of the well — you will feel a slight resistance when it settles on the well casing or the old pump's support.

Reconnect the pressure tank and restore power

Once the pump is in place, reconnect the water line from the pump to the pressure tank. Use a pipe wrench to tighten the fitting. Open the drain valve on the tank slightly to let air out as water fills it, then close the valve once water begins to flow.

Go back to the electrical panel and switch the pump breaker to the on position. The pump should start automatically and begin filling the pressure tank. Listen for normal operation — the pump should run for a few minutes, then shut off once the tank reaches its set pressure (usually 40 to 60 pounds per square inch).

Check all the connections for leaks. If you see water dripping from the drop pipe connection or the electrical connector, turn the pump off, drain the tank, and tighten the fitting. Once everything is dry and the pump cycles normally, the job is complete.

When to call a contractor instead

If your well is deeper than 25 feet, the pump is too heavy to pull safely by hand, and the risk of dropping it into the well is high. A dropped pump can crack the well casing and contaminate your water supply with bacteria. A licensed well contractor has a truck-mounted winch and the experience to pull and install pumps in deep wells without damage.

You should also call a contractor if the drop pipe is corroded and stuck, if the electrical cable is damaged, or if you are not confident working with electrical connections. A contractor will also pressure-test the new pump and check the water quality before leaving, which gives you peace of mind that the job was done right.

Frequently Asked Questions

How do I know what size pump to buy?

Check the nameplate on your old pump for the horsepower, voltage, and depth rating. Write these down and buy a pump with the same specs. If the nameplate is missing or illegible, measure the well depth with a weighted string and count the number of feet. A well contractor can also identify your pump size from a photo.

Can I use a different voltage pump than the old one?

No. If your old pump was 240V, the new one must be 240V. If it was 120V, the new one must be 120V. Using a different voltage will either not work at all or will damage the pump. Check your electrical panel to see what voltage is available to the well breaker.

What if water is still coming out of the well after I pull the pump?

That is normal — the well casing holds water above the pump. Let it drain into a bucket. If water keeps flowing after several minutes, the drop pipe may be cracked or the pump may not have been fully disconnected. Stop and check both connections before proceeding.

How long does it take to replace a submersible pump?

For a shallow well with a helper, plan on two to four hours from start to finish. This includes draining the system, pulling the pump, disconnecting and reconnecting lines, lowering the new pump, and testing it. Deep wells or stuck connections can take longer.

Do I need to disinfect the well after installing a new pump?

If the well was open to the air while you worked, it is a good idea to disinfect it. Your local health department can advise you on the process, which usually involves adding bleach to the well and running water through the system for several hours. Some contractors include this step as part of the job.