What is a well pump?
Updated August 2026
A well pump is the electric pump that pulls water out of a private well and pushes it into the home's plumbing at usable pressure. Two designs cover almost every house. A submersible is a long cylinder, 3 to 4 inches across, hanging on the drop pipe anywhere from 30 to 300 feet down inside the casing, pushing water up. A jet pump sits above ground in a basement or well house, pulls by suction, and works only on shallow wells, generally under 25 feet for a shallow-well model. Either way, the pump feeds a pressure tank rather than the taps directly.
Where it is
Where you look depends on which type you own. A submersible gives away nothing at the surface except the well cap, a 6-inch steel or plastic lid standing 12 to 18 inches above the yard with electrical conduit running back to the house. A jet pump is impossible to miss: a cast-iron or stainless body about the size of a bread loaf, bolted near the pressure tank, with a suction line heading out toward the well. Trace the water line backward from the pressure tank and you land on one or the other. Note the pump's dedicated breaker while you are there, since that is the first thing a technician asks about.
What it does
The pump runs only when the pressure switch calls for it, refilling the tank from a cut-in near 40 psi up to a cut-out near 60. Everything the house does with water happens on that stored charge. Trouble shows up in a fairly reliable order. Air spitting from faucets means the water level fell below the intake or a suction line is drawing air. Pressure that fades midway through a shower points at a worn impeller stack. A pump that starts and stops every 20 to 30 seconds is rarely the pump's fault; that is a waterlogged pressure tank, and left alone it burns out a healthy motor in a season. Silence with a tripped breaker means a seized motor or a dead control box capacitor. Most pumps run 8 to 15 years.
Maintenance
Treat the well as a system and test it twice a year: read the gauge through a full cycle, time how long the pump runs, and listen for rapid cycling (well pump testing). Send a sample for bacteria and nitrates once a year, and lift the well cap to confirm the seal and screened vent are intact, because a cracked cap is how surface runoff and insects get in. Most states set 50 to 100 feet of separation between a wellhead and any septic component. Track the pump on age rather than waiting for the dry morning: how long well pumps last and replacement timing set the clock, the well pump checklist holds the seasonal items, and the cost calculator puts a number on the reserve you should be building.
What it costs to replace
A replacement well pump runs $400–1,200 installed for a jet pump, or $1,500–3,000 for a submersible, since most of that bill is pulling the pump.
OnOtto's photo scan identifies parts like this in your home and builds the maintenance schedule for you. See how the scan works.
Frequently asked questions
Do I have a submersible or a jet pump?
Look for a pump inside the house. A cast-iron pump body near the pressure tank, with a pipe running out toward the well, means a jet pump and a shallow well. If the only hardware indoors is the pressure tank, the gauge, and the switch, the pump hangs down the well and is submersible. A gray control box on the wall about the size of a paperback is another submersible tell, since most single-phase submersible motors need one to start.
Why do my faucets sputter and spit air?
Air in the lines means the pump is drawing something other than water. On a submersible, the well level has dropped to or below the intake, which happens in drought, after heavy irrigation, or as a well silts in. On a jet pump, the suction line, foot valve, or a fitting is pulling air. Give the well 2 to 4 hours to recover and see whether it clears. If it returns every time you run water for 10 minutes, the pump may need lowering.
Can I replace a well pump myself?
A shallow-well jet pump is a fair weekend job for someone comfortable with plumbing and a 240-volt circuit. A submersible is not. Pulling 200 feet of pipe, wire, and pump weighs several hundred pounds, wants a truck-mounted hoist, and a dropped pump means fishing it out of the casing or drilling again. That labor is why the bill reaches $1,500–3,000 when the pump itself is often $400–900.
What kills a well pump early?
Three things, in order. Short cycling from a waterlogged pressure tank puts thousands of extra starts on a motor designed for a handful an hour. Running dry cooks the seals and bearings in minutes and follows a falling water table or an oversized pump. Sand from a failing well screen grinds the impellers away. Correct all three and 8 to 15 years is realistic. Ignore them and 4 years happens.