How long do well pumps last?

What ten to fifteen years is actually measuring

A submersible pump is a sealed motor hanging in water at the bottom of your well. Nothing inside it wears out on a calendar. It doesn't corrode from age and it doesn't have a timer. What wears it out is starts, heat and grit, and none of those three are measured in years.

So the honest unit isn't age, it's cycles. Two identical pumps come out of the same carton. One sits on a healthy 62 gallon tank in a two person house and starts eight or ten times a day. The other sits on a tank that lost its air charge in year three and starts every forty seconds anytime a faucet is open. The second racks up more starts in a month than the first does in a year.

Starting is the violent part. The instant a submersible energizes it draws several times its running current, the windings heat fast, and the thrust bearing takes the hit as the impeller stack lifts. Once it's running, water moving past the motor carries the heat away. Every piece of real advice about pump life is secretly advice about reducing starts.

That's why the ranges are wide. A four inch submersible in a drilled rock well runs eight to fifteen years as the ordinary spread. Sized right, in clean water, on a maintained tank, twenty is reachable. We also pull them at six, and those were abused rather than unlucky. An above ground jet pump runs eight to twelve, and it has one advantage: it sits in your basement with a shaft seal, so it drips and gets louder and you hear it dying. A submersible makes no sound at all until the day it makes no water.

The parts around the pump keep their own clocks, and every one is cheaper than the pump. A bladder tank goes five to fifteen years, a pressure switch three to ten, a check valve ten to fifteen. The drop pipe and cable hang in the same water for the same number of years as the pump, which is why on an older well we bring them up with it rather than sending twenty year old poly back down a 400 foot hole.

A variable speed constant pressure setup wears differently. It starts far less often and spends most of its life turning at part speed, which is easier on the motor. The tradeoff is that the drive electronics at the surface become a component with a life of their own, and on those systems the controller tends to fail first.

The six things that kill a pump early

Almost every early failure we bring out of a hole traces to one of these, and five of the six are fixable for a fraction of what a pump costs.

• Short cycling from a dead pressure tank. The biggest killer by a wide margin. A tank with no air charge has no drawdown, so the pump starts and stops every few seconds instead of running a real cycle. It turns one pump year into five. The tank is a same-day swap in most basements. The pump it ruins costs far more.
• Sand and silt. Grit grinds impellers, wears bearing surfaces and cuts seal faces. A pump hung too close to the bottom of the casing sits in the sediment pile and pulls it all day. Sand in the aerators is the pump telling you what it's eating.
• Running dry. On a low yield fractured rock well the water level drops to the pump during a long draw and the motor pulls air. Air cools nothing. A submersible that runs dry for a few minutes can be finished the same afternoon, and it's the one failure here that happens in a single event.
• Voltage problems. A loose lug in the panel, undersized wire on a long run to a detached well, a corroded splice at the pitless, or a weak leg from the utility. A motor fed low voltage draws more current to do the same work and cooks slowly. Invisible until the pump quits, and cheap to check with a meter.
• Iron bacteria. An organism that lives on dissolved iron and builds reddish brown slime through the casing, the drop pipe and the pump screen. It restricts flow, plugs the intake, and over years lays down enough deposit to cement pipe and pump into the casing. Deal with it before it turns a pump job into a retrieval job.
• The wrong pump for the well. Oversized is as damaging as undersized. A ten gallon per minute pump in a well that makes four drains the standing column and spends its life fighting for water. Low flow submersibles exist for that reason and cost somewhat more than a standard unit.

Why the same pump lasts twenty five years here and six years next door

Two houses in Vernon, half a mile apart, same pump model, same installer, same year. It happens, and the outcomes aren't close.

The one that goes twenty five: a 320 foot rock well making eight gallons a minute that never draws down, a 62 gallon tank whose precharge somebody checked twice a decade, no measurable iron, a solid 240 volt feed, two adults. That pump starts a handful of times a day and runs a full minute each time. It's doing almost nothing.

The one that goes six: a 260 foot well making two and a half gallons a minute that draws down every August, a 20 gallon tank flat since year three, iron and fine sand in the water, undersized wire out to a detached wellhead, a family of five and a sprinkler zone. It short cycles all summer, breathes air in a dry September, and runs hot the whole time.

The pump is the most expensive component in the system and the one with the least control over its own fate. Everything that decides its life happens somewhere else: at the tank, at the panel, at the wellhead, and on the day it was sized.

How to find out how old yours is

The pump is a few hundred feet out of reach, so you date it from the evidence around it. Start with paperwork. New Jersey has required a permit and a well record for decades, and those records give you the drilling date and often the depth. The county health department and the municipal building department are where to ask. That dates the well, not the pump, but an original pump in a 2004 well gives you a ceiling.

Then look at the hardware. A contractor's sticker on the pressure tank, the well cap, the switch cover or the panel is the most common date you'll find, and plenty carry a handwritten one. Pressure tank labels have a manufacturing date code, and a three wire pump has a control box on the wall dated inside the cover.

Then ask people. The prior owner, your own home inspection report, and any invoices in the basement drawer.

If nothing turns up, date the pump to the newest thing near it you can date, and treat anything past twelve years as a system to plan for rather than react to. Your well depth and who you'd call are the two answers everybody scrambles for the morning the water stops.

What genuinely buys you another decade

Check the pressure tank precharge every couple of years. Kill power, drain the system to zero at the lowest faucet, put a tire gauge on the Schrader valve on top of the tank, and confirm it reads 2 psi under your cut-in. On a 40/60 switch that's 38 psi. Ten minutes with a tire gauge and a bicycle pump is the highest return maintenance on a well system, because it directly reduces starts.

Size the tank up rather than down. A bigger tank is a few hundred dollars once and buys fewer starts for the whole life of the pump. Aim for at least a full minute of run time per cycle. Beyond that: set the pump with real water column above it and clearance below it, keep connections tight at the panel and the pitless splice, and put a low water cutoff on any low yield well, which costs far less than the motor it protects.

Then leave it alone. A pump that's been fine for eleven years doesn't need replacing because a chart says so. Watch the tank, watch the cycle times, and let it run. The tells that a pump is genuinely near the end show up in a fairly consistent order.

Any one of these on its own means little. Two or three inside a few months on a pump over ten years old is a pump telling you what's coming.

• Pressure that sags in the shower where it used to hold steady
• Longer run times to fill the same tank
• The pump kicking on when nobody is using water
• Sand or grit in the aerators and the toilet tanks
• Air spitting from faucets, especially after a long draw
• A breaker that trips once, then trips again a week later

When it is time

When it is time, depth drives nearly the whole cost of a submersible replacement. At 400 feet with new pipe and cable going back down, expect a substantially bigger number than a shallow swap. A jet pump swap in a basement is the small end of this work.

We install Grundfos and Goulds pumps with Amtrol Well-X-Trol tanks, every one of them under manufacturer warranty. On an older well the drop pipe and wire come out with the pump and new ones go back down, because they've hung in the same water for the same number of years. Wells are all we do, and that's been true here since 1952. Call 973-853-1550 if you'd rather somebody looked at yours first.