What you need to know before you start

Replacing a submersible well pump is a job you can do yourself if you have basic mechanical skills and the right tools, but it requires careful planning because the pump sits hundreds of feet down in your well. The process involves pulling the old pump and pressure tank out, disconnecting the electrical and water lines, lowering a new pump down the well casing, and reconnecting everything. Most homeowners either hire a well contractor (typically $1,500 to $3,000 for labour and parts) or rent a pump puller and do the work themselves over a weekend.

The hardest part is not the replacement itself — it is getting the old pump out of the ground. You will need either a pump puller (a mechanical device that grips the pump column and pulls it up) or a tripod with a winch. Renting these tools costs $50 to $150 per day. If you have never done this before, watching a video specific to your pump model is worth the time, because the exact steps vary depending on whether your pump is a jet pump (shallow well, usually under 25 feet) or a submersible (deep well, 25 feet or deeper).

Key Takeaways

  • Submersible pump replacement requires pulling the old pump out of the well casing, which demands a pump puller or winch rental unless you hire a contractor.
  • You will need to turn off power at the breaker, drain the pressure tank, and disconnect the electrical wire and water line before pulling the pump.
  • The new pump must match your well depth, flow rate, and voltage — buying the wrong size will not work and cannot be returned.
  • Lowering the new pump requires care to avoid damaging the well casing or the pump itself, and the electrical connection must be waterproof and buried below the frost line.
  • If you are unsure about any step, hiring a licensed well contractor is safer and often costs less than fixing a mistake.

Gather the right tools and equipment

Before you touch anything, rent or borrow a pump puller or arrange winch access. A pump puller is a mechanical clamp that bolts to the top of the pump column and uses leverage to pull the assembly straight up. A tripod with a hand winch or electric winch works if you do not have a puller. Do not try to pull a submersible pump by hand or with a rope — the weight (often 100 to 300 pounds) and the depth make this dangerous and ineffective.

You will also need: a pipe wrench or adjustable wrench (for disconnecting the water line), a screwdriver set, a voltage tester, a bucket, a flashlight, and a helper. If the electrical connection is buried in a junction box, you may need a shovel. Have the model number and specifications of your old pump ready before you start — you will need this to order the replacement. Write down the horsepower, voltage, flow rate (gallons per minute), and total dynamic head (the depth the pump can push water to).

Turn off power and drain the system

Locate the breaker that controls the well pump and switch it to the off position. Use a voltage tester on the pump's electrical wire to confirm the power is off — do not skip this step. A live wire in a wet environment is a serious hazard.

Next, turn off the main water valve to the house if you have one, or close the valve on the pressure tank. Open a faucet inside the house to release pressure from the tank. You should hear air hiss out. Leave the faucet open while you work. If water continues to flow after the pressure releases, there is a check valve in the line that is holding water in the tank — this is normal and you can proceed.

Disconnect the water line and electrical wire

The water line runs from the top of the well casing down to the pump. It is usually a single pipe (often 1 to 1.5 inches in diameter) that screws into a fitting at the top of the casing. Use a pipe wrench to loosen this connection — turn counterclockwise. Have a bucket ready because water will spill as you unscrew it. Once the pipe is loose enough to turn by hand, unscrew it completely and set it aside.

The electrical wire runs down the outside of the pump column inside the well casing. At the top, it connects to a junction box or directly to the breaker. If it is in a junction box, unscrew the cover and disconnect the wire terminals (usually by loosening a set screw or nut). If the wire is buried, dig down to expose the junction box. Take a photo of the wire connections before you disconnect them — you will need to reconnect the new pump the same way. Once disconnected, tape the end of the wire so it does not fall into the well.

Pull the old pump out of the well

Attach the pump puller to the top of the pump column according to the rental instructions. The puller clamps around the column and has a handle or bolt that you turn to create upward pressure. If you are using a tripod with a winch, position it directly over the well opening and attach the cable to the pump column.

Begin pulling slowly and steadily. The pump will resist at first because it has been sitting in the well for years and may have mineral buildup. Do not jerk or force it — steady pressure works better. As the pump comes up, guide the electrical wire so it does not snag on the casing. This process can take 30 minutes to an hour. Once the pump is out, lay it on the ground and disconnect the water line from the bottom of the pump if it is still attached. Do not throw the old pump away until you have confirmed the new one works — you may need it as a reference.

Prepare and lower the new pump

Before you lower the new pump, confirm it matches your well specifications. Check the nameplate on the pump for horsepower, voltage, flow rate, and maximum depth. If the new pump is rated for a shallower depth than your well, it will not work. If it is rated for a different voltage than your breaker supplies, it will not work. If you are unsure, contact the pump supplier or a well contractor.

Attach the water line to the bottom of the new pump using a pipe wrench. Wrap the threads with plumber's tape (also called Teflon tape) to create a watertight seal. Tighten firmly but do not over-tighten, which can crack the fitting. Attach the electrical wire to the pump according to the manufacturer's instructions — this usually involves connecting two or three wires to terminals on the pump motor. Wrap all electrical connections with waterproof tape or place them inside a waterproof connector.

Lower the pump slowly into the well casing using the winch or puller in reverse. Guide the water line and electrical wire as the pump descends so they do not twist or kink. Lower it until the pump rests on the bottom of the well or on the sediment screen (if your well has one). This is usually several hundred feet down, so the process takes time. Once the pump is in place, the water line at the top should be slack — this is correct and allows for thermal expansion.

Reconnect the water line and electrical wire

At the top of the well casing, screw the water line back into the fitting. Use a pipe wrench to tighten it firmly. Do not over-tighten — you want a seal, not a crushed fitting.

Reconnect the electrical wire to the junction box or breaker using the same connections you documented before. If the wire is buried, the junction box must be at least 12 inches below the frost line in your area (your local building department can tell you this depth). Bury the box and cover it with a weatherproof cap. Once everything is connected, turn the breaker back on and listen for the pump to start. You should hear a faint hum and feel water pressure building in the tank. Turn on a faucet inside the house — water should flow within a few seconds. If nothing happens, turn the breaker off when ready and check all connections.

Test the system and check for leaks

Let the pump run for 10 to 15 minutes. Check the pressure gauge on the tank — it should rise to between 40 and 60 pounds per square inch (psi), depending on your tank settings. If the pressure does not rise, the pump may not be primed (filled with water), or there may be an air leak in the water line.

Walk around the top of the well and look for water leaking from the connection where the water line enters the casing. A small drip is normal during the first few minutes as air is pushed out, but steady leaking means the connection is not tight. If you see a leak, turn off the pump, let the pressure drop, and tighten the connection with a pipe wrench.

Check the pressure tank for leaks as well. If water is dripping from the tank itself (not from a connection), the tank may have failed and will need to be replaced. Once the system has run for 15 minutes with no leaks and steady pressure, you are done. The pump should now run automatically whenever water pressure drops below the cut-in pressure (usually 30 to 40 psi).

Frequently Asked Questions

How deep can I lower a submersible pump?

The pump's nameplate lists a maximum depth rating — this is the deepest it can push water. Most residential submersible pumps are rated for 100 to 300 feet. If your well is deeper than the pump's rating, the pump will not be able to push water to the surface and will overheat. Always match the pump depth rating to your well depth.

What if the new pump does not start when I turn the breaker on?

First, confirm the breaker is actually on and the voltage tester shows power at the junction box. If power is there, the pump may not be primed — it may have air in the line instead of water. Turn off the breaker, loosen the water line at the top of the casing slightly, and let water run out until it flows steadily (no air bubbles). Tighten the connection and turn the breaker back on. If the pump still does not start, there may be a wiring error or a faulty pump — contact a well contractor.

Can I replace just the pump motor without pulling the whole pump?

Some submersible pumps have a motor that can be unbolted from the pump head, but this requires the pump to be out of the well and usually requires special tools. For most homeowners, it is simpler and safer to replace the entire pump assembly. A well contractor can advise whether your pump model allows a motor-only replacement.

How often do submersible pumps need to be replaced?

A well-maintained submersible pump typically lasts 8 to 15 years. Lifespan depends on water quality, how often the pump runs, and whether the pressure tank is serviced regularly. If your water is very hard or sandy, the pump may wear out faster. If you notice the pump running more often than usual or water pressure dropping, the pump may be failing and should be inspected by a contractor.

Do I need a permit to replace my well pump?

Most areas do not require a permit for pump replacement if you are replacing it with the same type and capacity. However, some counties require notification to the health department or a licensed contractor to do the work. Check with your local building or health department before you start. If you hire a contractor, they will handle any permit requirements.