Tank & Breaker
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Written by the Tank & Breaker editorial teamReviewed by Eric Jackov, plumbing & heating professionalReviewed Oct 20, 2026Fact-checked against 7 sourcesUpdated

How-to

Well Pump Replacement: How the Job Is Done

Short answer

A well pump replacement means one of two very different jobs. Swapping a jet pump that sits in the basement or well house is plumbing and wiring a homeowner can handle; replacing a submersible means pulling the pump, pipe and wire up out of the well and lowering a new one back down, which is a well contractor's job for most people.

Either way, the steps below show what should happen, what gets replaced alongside the pump, and where people go wrong.

Confirm the pump is the problem

Plenty of pumps get pulled that didn't need to be. Before you replace anything, rule out the cheap stuff: the breaker, the pressure switch contacts, the control box on a three-wire pump, and a waterlogged pressure tank. Our well pump not working checklist runs through it in order. A contractor should measure amps and resistance at the surface before quoting a pull.

Pick the replacement

WAYNE's advice is simple: if your water needs haven't changed, match the old pump's horsepower and voltage. Read the old pump's label or the control box before you buy.

Upsizing is tempting and often wrong. WAYNE notes that a bigger pump may need a bigger pressure tank to keep it from cycling too fast, and Boshart lists an oversized pump as a cause of pumping sand. See what size well pump you need before you change anything.

Replacing a jet pump

Tools and parts

WAYNE lists a screwdriver, pipe wrench, adjustable wrench, hacksaw, wire cutters, wire strippers and pipe clamps as the tools for installing its jet pumps. Add thread sealant or tape, a bucket, and water for priming.

Steps

  1. Shut off power and drain the system

    Breaker off, faucet open, gauge at zero.

  2. Label the wiring

    Take a photo of the pressure switch and motor connections before you disconnect them.

  3. Disconnect the piping

    Break the suction and discharge unions or fittings and lift the old pump off its base or tank bracket.

  4. Set the new pump

    WAYNE's jet pumps mount on a level floor or tank bracket. Make up the fittings with sealant and keep the suction line sloping up toward the pump.

  5. Wire it

    WAYNE says the pump must be permanently grounded before it's connected to power, and the wiring should be done by a licensed electrician to the National Electrical Code.

  6. Set the tank

    With the tank empty of water, WAYNE's manual sets the air pre-charge at 28 psi for its factory 30/50 pressure switch.

  7. Prime it

    Remove the priming plug, fill the pump and piping completely with water, replace the plug, open a faucet, and start the motor. If it hasn't primed within 5 minutes, stop, refill and try again.

  8. Run and check

    Let it flush for several minutes, close the faucets, and watch the pump shut off at cut-out.

Tap a number to tick off a step. 0 of 8 done.

Never start a jet pump dry. WAYNE warns that running it dry will damage the pump and void the warranty. The how to prime a well pump guide covers stubborn ones.

Replacing a submersible pump

This is the job most people mean when they search for well pump replacement. Here's what the crew does.

Equipment

A deep submersible is usually pulled with a pump hoist or a truck-mounted rig. On a shallow setting with plastic pipe, some homeowners and handymen use a manual puller or a T-handle tool that grips the pitless adapter, but it's still heavy work for two people. Have new wire splice kits, the replacement check valves, a torque arrestor if one was there, and safety rope ready before the old pump comes up.

Steps

  1. Kill the power and lock it out

    Breaker off at the panel, and if there's a control box, open it and confirm no voltage.

  2. Pull the well cap and find the pitless adapter

    The pitless is the fitting inside the casing that joins the drop pipe to the line to the house. A T-handle threads into it to lift the pipe free.

  3. Lift the pump out

    Pipe, wire and pump come up together. Lay the pipe out straight on clean ground and look at every joint and the wire for nicks.

  4. Read the old pump

    Note the horsepower, flow rating and voltage, and look at the intake screen. Sand, scale or a burned smell tells you why it failed.

  5. Build the new string

    Splice the motor leads with a waterproof splice kit. Goulds suggests copper wire only, a ground wire at least as large as the supply wires, and the wire taped to the drop pipe every 10 feet.

  6. Install check valves

    Goulds says to put one every 200 feet in the vertical discharge pipe. Boshart notes the first check valve is usually built into the pump, and puts the next one no more than 25 feet above the pumping level.

  7. Set the depth

    Goulds recommends setting the pump 10 feet above the bottom of the well and keeping the motor at least 5 feet under water. Boshart says a pump set too low pulls in sand, and that raising it 10 to 20 feet can stop that.

  8. Lower it back in and seat the pitless

    Go slowly so the wire doesn't scrape on the casing.

  9. Reconnect and start it with the valve partly closed

    Goulds says to throttle the discharge valve to about one-third open on first start, then open it up once the water runs clear.

  10. Set the switch and tank

    Goulds sets tank pre-charge 2 psi below the cut-in pressure, so 28 psi for a 30/50 switch, and mounts the pressure switch no more than 4 feet from the tank. Check it on our pressure tank air pressure page.

Tap a number to tick off a step. 0 of 10 done.

HomeGuide says an installer typically replaces a well pump in about 3 to 6 hours, longer on a deep or awkward well.

What to replace while the pump is out

You're paying to pull the pump, so look hard at everything that came up with it.

  • Check valves. Cheap, and a leaking one makes the pump cycle or run water back down the well.
  • Wire and splices. Nicked insulation or a corroded splice is a common cause of a tripping breaker. Goulds lists damaged cable and bad splices among the reasons a motor won't run.
  • Drop pipe. Old plastic pipe gets brittle at the threads.
  • Pressure switch and gauge. A gauge that sticks makes every later diagnosis harder. A new switch is inexpensive while you're there. See how to replace a well pressure switch.
  • Pressure tank. If the bladder has failed, the new pump will short cycle from day one.

Mistakes to avoid

  • Dropping the pump. Tie a safety rope to the pump and keep a hand on the pipe at all times. A pump at the bottom of a well is a fishing job for a contractor, and it can block the well.
  • Wrong control box. Three-wire pumps need a control box matched to the motor. Goulds lists the wrong control box among the reasons the thermal protector trips.
  • Setting it too low. A pump near the bottom pulls sand and wears out early.
  • Skipping the tank check. Pre-charge set wrong is how a new pump short cycles itself to death.
  • Ignoring voltage. Goulds says voltage more than 10% off the motor rating will damage motors and controls, and that's not covered by warranty.

When it's a pro job

Hire a licensed well contractor for a submersible, a deep well, a pump that's stuck, or any well where you don't know the depth. Goulds itself says its residential water systems are designed to be installed by qualified professionals, and it offers no warranty on its equipment bought over the internet. Many states license pump installers, so check with your local health or building department before you do the work yourself. Our well pump replacement cost page shows what a pro charges.

FAQ

How do you pull a well pump out?

Shut off the power, remove the well cap, thread a T-handle into the pitless adapter, and lift the pipe, wire and pump straight up together. Deep or heavy pumps come out with a pump hoist. Tie a safety rope on before the pump clears the water.

Can I replace a well pump myself?

A jet pump above ground, yes, if you're comfortable with plumbing and the wiring follows code. A submersible is heavy, the splice has to be watertight, and a dropped pump can ruin the well, so most homeowners hire it out.

How deep should a submersible well pump be set?

Goulds recommends 10 feet above the bottom of the well with at least 5 feet of water over the motor. Your driller's log and the old pump's setting are the best guide for your well.

How long does it take to replace a well pump?

HomeGuide puts a typical replacement at about 3 to 6 hours. Deep wells, corroded fittings and stuck pumps take longer.

What else should be replaced with a well pump?

Check valves, wire splices, worn drop pipe, the pressure switch and the gauge are the usual add-ons. Check the pressure tank too, since a failed tank makes a new pump short cycle.

Sources

Trade reviewReviewedReviewed by Eric Jackov, plumbing & heating professional with Plumbing Cor Inc, Bayside, NY, on Oct 20, 2026.
Updated

Eric works under NYC Master Plumber License #2128, held by John D'Auito (Tru-Flo Mechanical, Inc.), NYC Department of Buildings. Verify on the DOB list (opens in a new tab)

The numbers on this page come from the sources listed above. How we research and check pages