How long does a well pump last?

The short version

Well pumps have no standard lifespan that holds across wells, so no single number of years is reliable. What is documented is what wears a pump out. For best system life, a Franklin Electric submersible motor should average no more starts per day than the company recommends.^[1] A pump in a well-designed, well-kept system that starts a modest number of times a day is in a better position than the same pump in a system that short-cycles, runs on poor voltage or draws sand.

So the practical question is not only "is my pump old?" but "is anything wearing it out faster than it should?" Most of the answers are above ground, in the pressure tank, the switch and the power supply.

What wears a pump out

How often it starts. Starting current builds heat in the motor, and the starts add up. Excessive cycling shortens the life of the control components and can damage the motor's splines and bearings or overheat it.^[1] For scale, Franklin Electric's recommended maximum for its encapsulated single-phase motors of 1 to 5.5 horsepower is 100 starts in 24 hours, and 300 for its motors up to 0.75 horsepower.^[1] Its motors should also run at least one minute each time they start, so the heat built up by the starting current can dissipate.^[1]

The pressure tank. The tank is part of how a system limits starts: the pump size, the tank size and the other controls are chosen to keep the starts per day as low as possible.^[1] When the tank fails, the pump pays for it. A waterlogged tank causes rapid cycling.^[1] Our guide to a pump that keeps turning on and off covers the signs.

Voltage. Incorrect voltage can make a running motor trip its overload. The voltage at the line terminals must be within 10% of the motor's rated voltage, and the remedy when it is not is to contact the power company.^[1]

Lightning and surges. "All submersible motors require a dedicated surge arrestor."^[1] Some come with one: motors of 5 horsepower and smaller marked "Equipped with Lightning Arrestors" have one built in.^[1] Ask your contractor whether yours is protected.

Cooling. A submersible motor is cooled by the water moving past it. Franklin Electric's submersible motors need water flowing past them along the whole length of the motor to stay cool.^[1] Some installations need a flow inducer sleeve to get that flow, including a well whose diameter is too large and a pump set below the well casing.^[1] That is a question for the installer, and one more reason to use someone who knows wells.

Matched parts. On motors with an above-ground control box, the control box's horsepower rating and voltage must match the motor exactly, or the box or the motor can be expected to fail early.^[1] A mismatched box left over from an earlier repair can shorten a new motor's life.

Sand and sediment. A sand-locked pump can bind so the motor cannot turn.^[1] A well that produces sand is a well problem as much as a pump problem.

Signs a pump is wearing out

A worn pump is one of the reasons a motor runs continuously without shutting off, and a worn pump can also make the motor draw lower current than normal.^[1] Those signs overlap with other faults: the symptoms of a worn pump are similar to those of a leak in the drop pipe or a low water level in the well.^[1] That is why a good contractor tests before replacing, including checking the motor's running current against its specifications,^[1] rather than pulling the pump on a guess.

What keeps a well system healthy

Most of the upkeep that protects a pump is checking and scheduling, not tools:

• Test the water every year. Test the water once a year for total coliform bacteria, nitrates, total dissolved solids and pH.^[2] The Virginia Department of Health also recommends testing once a year.^[3] Then test again immediately after any part of the well system is replaced or repaired.^[2]
• Look at the wellhead. Check the exposed parts of the well now and then for cracked, corroded or damaged well casing, a broken or missing well cap, and settling and cracking of surface seals.^[2]
• Keep the area clear. Virginia's well regulations say: "No objects, articles, or materials that are not essential to the operation of the well shall be placed or stored in a well, well house, on the well head or well pump or water treatment system, or within close proximity to them."^[4] They also say the area around the well must be graded to divert surface water away from it.^[4]
• Keep records. Keep records of the well's installation and maintenance, any treatment devices, and every water test.^[5] It helps to add when the pump, tank and switch were installed, the pump's make and horsepower, and the switch settings, so the next contractor can quote faster and more accurately.
• Pay attention to cycling. If the pump starts every time you open a tap, get the tank and switch checked before the motor suffers.

After any repair, ask about disinfecting the well. Virginia Cooperative Extension recommends shock chlorination following any maintenance or repair of a private water supply system.^[6]

When to call a licensed pro

The checks above are a homeowner's; the repairs are not. Virginia's private well regulations say: "Persons engaged in the construction, repair, or alteration of a private well shall be licensed and certified".^[7] Installing the well pump and tank is part of the Board for Contractors' water well and pump specialty,^[8] and its definition does not exclude licensed plumbing, electrical or HVAC contractors from installing pumps and tanks.^[8]

Call a licensed well or pump contractor, or a plumber who does well work, when the pump cycles rapidly, runs without stopping, trips its breaker, or pressure is falling off; when the water turns cloudy or sandy; or after a lightning strike or flood near the well. Before you hire, check the contractor's licence. If it does come to a replacement, what drives the cost explains what to ask for in a quote.

Find a well pump pro

Loclis lists licensed businesses from Virginia's DPOR register. Browse well pump services or well water testing, see more plumbing answers, or describe the job once and licensed local businesses quote it.