A well pump almost never dies without warning. It sends signals for months, and most of them get blamed on the well, the weather or the plumbing before anyone suspects the pump.
Knowing which symptom points at the pump and which points somewhere cheaper saves the most common wasted expense in well ownership, which is replacing a working pump because a twenty dollar part failed.
How Do You Tell If a Well Pump Is Bad?
A well pump is bad when it draws the wrong current for its nameplate, fails to build pressure with a healthy tank and switch, or runs without delivering water. Falling pressure on its own is not enough, because the pressure switch and tank cause the same symptom far more often than the pump does.
Key Takeaways
- Check the pressure switch and tank before suspecting the pump.
- Amp draw against the motor nameplate is the fastest real test.
- Short cycling is a tank problem, not a pump problem.
- Sand in the water damages the pump but starts with the well.
- A dry well recovers after a rest. A dead pump does not.
Seven Signs a Well Pump Is Failing
1. Pressure drops or swings
Falling pressure is the most reported symptom and the least specific. A worn impeller does cause it, but so does a failing pressure switch, a waterlogged tank or a partly closed valve. Rule out the cheap parts first, in that order.
2. The pump runs and will not shut off
A pump that never reaches cut-out is either losing water somewhere or no longer able to make pressure. Check for a leak and a stuck check valve before condemning it, because a pump running continuously is also destroying itself while you decide.
3. It starts and stops every few seconds
Short cycling is a pressure tank symptom in almost every case. The tank has lost its air charge, so the pump has nothing to rest against. Left alone it will wear out a healthy pump through sheer number of starts.
4. Air spits from the taps
Spitting means air is entering the system, usually because the water level has dropped to the pump intake or a suction line is leaking. On a submersible it often means the well is struggling rather than the pump.
5. Sand or grit in the water
Sand means the well screen or casing is letting solids through, and every hour of that grinds away the pump’s clearances. The well is the root cause here, but the pump pays for it, and this is the fastest way to wear one out.
6. The electric bill climbs
A pump losing efficiency runs longer for the same water, and it shows up on the bill before it shows up at the tap. Compare against the same month last year rather than last month, since usage is seasonal.
7. Noise, or sudden silence
Grinding and rumbling point at bearings. A click followed by nothing usually means a failed capacitor or start relay in the control box, which is a cheap fix and often mistaken for a dead motor. Where the pump is genuinely finished, replacements sit in the 4 inch submersible well pump range.
How to Test a Well Pump Without Pulling It
Testing from the surface answers most of the question and costs nothing but time. Three checks in order:
- Voltage at the pressure switch. No voltage means the fault is upstream, in the breaker, wiring or switch.
- Amp draw against the nameplate. High current suggests a binding pump, low current a worn impeller moving less water than it should, and zero current an electrical fault.
- Insulation resistance on the motor leads. A low reading means water has reached the windings, and that pump is finished.
If all three read normal and you still have no water, the problem is more likely the well than the pump.
Is the Well Dry, or Is the Pump Dead?
These get confused constantly because they look identical at the tap. The difference shows up over time rather than in the moment.
| Symptom | Dry or low well | Failed pump |
|---|---|---|
| After an hour with the pump off | Water returns | Still nothing |
| Air spitting at the taps | Common | Rare |
| Sediment when flow returns | Common | Rare |
| Amp draw | Normal or low | High, low or zero |
| Pattern | Worse in dry season | Worse over months |
Running a pump in a well that has dropped below the intake is what turns a dry season into a replacement, since the pumped water is also what cools the motor. Our guide to well pump servicing covers the protection that prevents it.
Repair or Replace?
Replace the pump when the motor has failed, the impellers are worn, or a second significant repair lands on a unit already past ten years. Repair everything else, because pressure switches, capacitors, check valves and tanks are cheap and they protect the pump.
Age matters more than people expect on a submersible, because most of the cost is pulling it out of the well. Once a rig is on site, fitting a new pump rather than a repaired one is usually the better value. The wider comparison of pump families is set out in our look at well pumps against surface units.
Where the symptoms are pressure related rather than pump related, work through common pump faults first.
Frequently Asked Questions
How do you tell if the well is dry or the pump is bad?
Tell a dry well from a bad pump by how the water behaves after a rest. A dry well recovers: shut the pump off for an hour and you get water again, usually with air spitting and sediment first. A failed pump gives you nothing no matter how long you wait. Measure the static water level if you can, because that settles it either way.
Can you test a well pump without pulling it?
Yes, you can test a well pump without pulling it, and you should before paying anyone to lift it. Measure amp draw at the control box and compare it against the motor nameplate. High amps point to a binding pump, low amps to a worn impeller, and no amps to a wiring or switch fault. An insulation resistance test on the motor leads finds a failed winding.
Why does a well pump short cycle?
A well pump short cycles because the pressure tank has lost its air charge, not because the pump is failing. Water is nearly incompressible, so without that cushion the pump reaches cut-out instantly and starts again seconds later. Check the tank precharge with a tire gauge, pump off and system drained. It should sit about 2 psi below cut-in pressure.
How long do well pumps last?
Well pumps last around 8 to 15 years, with submersibles usually outliving jet pumps because they run cooler and start less often. Sand, short cycling and frequent starts are what cut that short. A pump failing well before the decade mark almost always points at the pressure tank rather than the pump.
If the pump does turn out to be the failed part, we break down what a replacement costs and where the money actually goes.
Replacement Pumps and Parts
Ken’s Distributing stocks Franklin Electric well pumps along with the switches, capacitors and control boxes that fix the faults above without a new pump. The full range is covered in our overview of Franklin pump options, or send us your well depth and flow and we will confirm the right unit.
Cost figures cited from This Old House.