Do this first
- Shut the pump off at the breaker. A submersible motor is cooled by the water moving past it, and hours of running against little or no flow cooks the windings.
- Before you kill power, watch the gauge for a full minute. Sitting at 35 and never climbing, climbing to 55 and stalling, or bouncing every few seconds each mean something different. Write down what you see.
- Close the main valve between the pressure tank and the house, then power the pump for two minutes. Pressure builds and the pump shuts off means the water is going somewhere inside. Still running means it's the tank, the switch, the pump or the well.
- Check every toilet. Put a few drops of food coloring in the tank, don't flush, wait fifteen minutes, and look in the bowl. Color in the bowl means the flapper is passing water, silently, all night.
- Rap your knuckles up the side of the pressure tank. Hollow on top and solid at the bottom is healthy. Solid all the way up means it's full of water and has lost its air charge.
- Call 973-853-1550 with the gauge numbers, the result of the valve test, and roughly how old the pump is.
Why a pump that never stops is urgent
A submersible pump has no fan and no air around it. The water it pushes past the motor shell on its way up the well is the only thing carrying heat away. When the pump runs and moves very little water, or pulls a mix of water and air because the level is low, that cooling goes away and the heat stays in the motor. Windings and bearings are what give up.
It doesn't take long. A pump with eight good years left in it can be scrap by Monday. We've pulled motors that were black inside after one weekend of running while the family was away and a line was leaking under the yard. Nothing in the house looked wrong when they got home except the water was off.
There's slower damage happening at the same time. A pressure switch holding a motor on for hours arcs and heats its contacts, and control box components on a three wire setup cook. The electric bill is the smallest part and it's still real: a half to one horsepower submersible pulls roughly 5 to 10 amps at 230 volts, and around the clock that adds up by the end of a month. It's cheap next to the pump.
The one test that splits the problem in half
Do this before anything else, because it cuts the list of suspects in half in about three minutes. Every well system has a valve where the line leaves the pressure tank and heads into the house. Find it. It sits on the tank tee or a few feet past it, ahead of the sediment filter and any treatment gear, and it's the boundary between what the well is doing and what your plumbing is doing.
Close that valve and leave the pump powered. Watch the gauge for two or three minutes. If the pump builds to its cut-out setting and shuts off, the well side of your system just proved itself. The pump, the well, the tank and the switch all did their jobs by satisfying a closed system. Water is escaping somewhere in the house, and that's where you go looking.
If the pump keeps running with that valve closed, and the gauge sits at 35 or climbs partway and stalls, the problem is on the well side. Nothing downstream can explain it. Now it's the tank, the pressure switch, the pump itself, or the water level in the well.
Two cautions. Don't let the pump run more than a few minutes during the test, especially if pressure isn't climbing. And notice where that valve sits relative to your buried service line. If the valve is inside the basement, the buried run from the wellhead is on the well side of the test, so a leak out in the yard reads as a well side problem when it isn't one.
House side: what's draining the system quietly
A toilet flapper that doesn't seal is the most common cause we find, and it's the one nobody believes. A worn flapper can pass a couple of gallons a minute straight down the drain, which is more than a lot of wells around here even produce, and it makes no sound at all. The food coloring test settles it in fifteen minutes. Check every toilet in the house, including the one in the basement nobody uses.
After toilets, work outward. An outside hose bib cracked open or left with a hose on a sprinkler. A frost free spigot that split over the winter and only leaks while the valve is open. An irrigation zone valve that isn't seating and is watering the lawn all night. A water softener stuck in a regeneration cycle sends water straight to a floor drain for hours, and that one is genuinely invisible: put the softener in bypass for a day and see if the pump calms down.
Then the ones that hide. A relief valve on the water heater weeping into a drain, a boiler autofill quietly making up for a leaking heating loop, a humidifier or ice maker line, a split line under a slab, or a buried branch running out to a barn or a frost free hydrant. If the house is on a well and you have outbuildings, valve those branches off one at a time and repeat the test. That narrows it to a single run without digging anything.
Well side: the four that keep a pump running
The pressure switch is holding it on. The switch carries the motor's full current across two small contacts, and every start arcs them. Contacts that fuse closed keep the motor energized regardless of what the water is doing. A switch whose sensing tube has packed with iron and scale is worse in a way, because it's a perfectly good switch reading a stale number: if it clogged at low pressure, it never sees the system reach cut-out and it never opens. Somebody turning the cut-out screw up past what the pump can deliver does the same thing. Don't open the cover to look. That box carries 240 volts on two hot legs with no neutral, mounted on a wet pipe.
The tank has lost its air charge. A waterlogged tank more often shows up as short cycling, on and off every few seconds, but a badly failed one paired with any small leak reads as a pump that simply never satisfies. Check it properly: breaker off, open a faucet and drain the gauge to zero, then put a tire gauge on the air valve at the top of the tank. You want 2 psi below cut-in, so 28 psi on a 30/50 system or 38 psi on a 40/60. Water spraying out of that valve means the bladder is torn and the tank is finished.
The pump can't reach the cut-out setting anymore. Impellers wear, and sand accelerates it. A pump that used to hit 60 psi in ninety seconds now tops out at 44 and sits there. The switch is set to open at 60, so it never will, and the motor never stops. The clean test is to close the house valve and watch: a healthy pump satisfies a closed system fast. One that stalls 15 psi short of cut-out with nothing drawing has told you what it can and can't do.
The water level is falling out from under it. This is the one people miss, because the pump was fine last year. As the level in the well drops, the pump has more lift to do, and every 2.31 feet of extra lift costs about 1 psi at the tank. Let the pumping level fall 100 feet below where it used to sit and you've taken roughly 43 psi off what that pump can deliver to the house. A pump comfortably making 60 psi in April can't reach 50 in September, so the switch never opens. It comes with spitting faucets and cloudy water, and it's a well problem wearing a pump costume.
What we test when we get there
We clamp an ammeter on the pump leg and compare the draw to the motor's nameplate. A pump straining against a restriction, a pump running dry and a pump doing normal work each pull a different current, and that single reading rules out a lot before anybody touches a wrench.
Then we sound the well. A level meter down the casing gives a real static number, and running the pump while we watch shows the drawdown rate and the recovery rate. A well that drops 200 feet in ten minutes and comes back slowly is a yield problem, and no new pump fixes a yield problem.
If the house is losing water and nobody can find it inside, we isolate and pressure test the buried run from the pitless adapter to the house. A line leaking under a lawn shows no wet spot and makes no sound. It shows up as a pump that never stops, and a pressure test on that isolated run is the only thing that proves it.
What the fix costs
A toilet flapper is a few dollars and twenty minutes. A pressure switch is a cheap part, and a switch replacement is an ordinary service call once you count the diagnosis and the sensing tee. A pressure tank that's lost its bladder is generally a same-day swap. A worn pump on a deep rock well is the expensive end, and higher again on a 500 foot well, because the pipe and wire come out with it.
You'll get the price before the work starts, with the reason for each line on it. If the honest answer is that your pump has six more years in it and you have a toilet flapper problem, that's what we'll tell you, and we've told plenty of people exactly that.
Call 973-853-1550 with the gauge numbers and the result of the valve test. Knowing whether the pump satisfies a closed system is the single most useful thing you can hand us, and a fair number of these calls get sorted on the phone in five minutes without anybody driving out.