System guide
Signs Your Well Pump Is Failing — and What Mimics Them
A worn pump and a $200 part can produce exactly the same complaint at the faucet. Here is how to tell which signs point at the pump, and what should be measured before anyone pulls it.
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A pump that is wearing out usually shows it slowly: it takes longer to refill the pressure tank, struggles to reach the cut-out pressure, or delivers less water than it used to. The trouble is that Franklin Electric's troubleshooting guide says 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] Tanks, switches, control boxes and check valves cause many of the same complaints for a fraction of the price. Age alone isn't a diagnosis either — HomeGuide reports typical lifespans of 8 to 15 years.[2]
The signs, and what else causes each one
Read this table left to right. The third column is the reason not to buy a pump on symptoms alone.
| What you notice | Why a worn pump does this | What else does it | Check first |
|---|---|---|---|
| The pump runs longer than it used to, or never shuts off | Worn impellers can no longer build the cut-out pressure | A leak, a low water level, a switch set too high, a check valve stuck closed, a blocked intake screen | Pump keeps running |
| Weaker pressure and flow than a year ago | Pump output has dropped | Clogged filter or softener, wrong tank precharge, scaled-up pipe | Low water pressure |
| The breaker trips, or the pump stops and restarts later | A sand-bound or failing motor draws too much current | Control box, damaged cable, low voltage, a hot control box location | Breaker keeps tripping |
| Clicks or hums but won't start | Motor or pump is seized | Start capacitor or relay in the control box, pitted pressure switch contacts | Pump won't turn on |
| Air or sand spitting from faucets | Sand wears impellers; a pump drawing air is near the water level | Falling water level, hole in the drop pipe, failing check valve, gas in the water | Air in water lines |
| A higher electric bill with no other explanation | The pump runs longer to deliver the same water | A running toilet or hidden leak, irrigation, a pump that can't reach cut-out | Running cost |
| No water at all | Motor failure | Tripped breaker, pressure switch, low-pressure cutoff, lost prime, frozen pipe | No-water triage |
The pump-side causes in the first, third and fourth rows come from Franklin Electric's system troubleshooting tables, which list a worn pump under "motor runs continuously," a bound pump under "motor does not start," and a worn pump or motor under "motor runs but overload protector trips."[1]
Two signs that usually aren't the pump
- The pump starts every few seconds
- Franklin's list of causes for "motor starts too often" has four entries — the pressure switch, a check valve stuck open, a waterlogged tank and a leak in the system — and the pump isn't one of them.[1] Square D's troubleshooting table for rapid cycling points the same way: tank, air charge, leak or check valve.[3] Start with short cycling. Left alone, though, rapid cycling is one of the things that does ruin a pump.
- Pressure that swings up and down in the shower
- That is the normal 20 psi gap between cut-in and cut-out, made more noticeable by a small or waterlogged tank. See how to tell if a pressure tank is bad.
How long well pumps last
We haven't found a pump manufacturer that publishes a guaranteed service life, so the figures in circulation come from cost publishers. HomeGuide gives 8 to 15 years in its repair guide — adding that submersible pumps often last longer than jet pumps — and 10 to 15 years in its replacement guide.[2][4] Treat those as typical ranges, not expiry dates. What the manufacturer documentation does spell out is what shortens a pump's life:
| Cause | What Franklin says | What you can do |
|---|---|---|
| Too many starts | A minimum run time of one minute per start, and no more than 300 starts a day for motors up to ¾ HP or 100 a day for 1 to 5 HP single-phase motors | Keep the pressure tank charged and correctly sized |
| Failed or missing check valves | Backspin, upthrust and water hammer — any of which "can lead to early pump or motor failure" | Act on check valve symptoms early |
| Wrong voltage | Supply must be within 10% of the motor's rated voltage | Report dim lights or brownouts when the pump starts |
| Sand | A sand-bound pump draws 3 to 6 times normal current until the overload trips | Mention any grit in the water to your contractor |
| Surges and lightning | The installation checklist calls for a dedicated surge arrestor | Ask whether one is fitted |
All from Franklin's application and maintenance manual.[1] A yearly look at the system catches most of these early: see the maintenance checklist.
How a contractor confirms the pump is the problem
Professional-only
Every test below is done on live or recently live equipment with meters most homeowners don't own. They're listed so you know what to ask for — not to do yourself.
- Running current
- The technician clamps an ammeter on the motor leads and compares the reading with the manufacturer's table. Franklin notes that low amps may be caused by a worn pump, a pump running at shut-off, or stripped splines, while a bound pump shows locked-rotor amps and trips the overload.[1]
- Insulation resistance (a "megger" test)
- Measured from the surface with the power disconnected, this shows whether the motor windings or the cable have lost their insulation. Franklin's table for a motor in the well: 2.0 megohms or more reads like a new motor, 0.5 to 2.0 megohms is a motor in good condition, and below 0.5 megohm means insulation damage to locate and repair.[1]
- Winding resistance
- An ohmmeter reading across the motor leads shows a shorted or open winding, or a bad cable joint.[1]
- The pressure-switch test
- For a pump that won't shut off, Franklin's procedure is to reduce the pressure switch setting: if the pump then shuts off, worn parts may be the fault.[1]
- Water level
- Static and pumping (drawdown) levels measured at the wellhead tell a low well apart from a weak pump.[1] A new pump does nothing for a well that has run low.
Ask for the readings in writing. A diagnosis of "the pump is shot" with no numbers attached is a reason to get a second opinion.
Repair-or-replace checklist
This tool is for educational guidance and does not replace an onsite diagnosis. It applies published rules of thumb (HomeGuide) and manufacturer guidance (Franklin Electric); it gives you questions to ask, not a verdict.
Repair or replace: the rule of thumb
HomeGuide's guidance is to consider replacement when the pump is more than 10 to 15 years old, especially after several recent repairs, and to repair newer pumps with a single failed component — particularly when the repair costs less than half of a replacement.[2] For scale, it puts the average repair at $300 to $600 and a submersible pump replacement at $1,000 to $2,500 installed.[2][4]
One practical wrinkle with submersibles: any repair down the well means pulling the pump, and that labor is the same whether the old pump or a new one goes back in. That is why contractors often suggest replacing an older pump once it's out. It can be reasonable — ask for both prices.
Signs to act on today
Switch the pump's breaker off and call
- The pump runs and the gauge stays near zero.
- The breaker trips a second time after one reset.
- You smell burning, see scorch marks, or the control box is hot.
- Pipes bang hard each time the pump starts.
Sources
- Franklin Electric. Submersible Motors: Application, Installation & Maintenance (AIM) Manual, 60 Hz. Accessed Sept. 28, 2026.
- HomeGuide. How Much Does Well Pump Repair Cost? (article dated Aug. 6, 2025). Accessed Oct. 8, 2026.
- Schneider Electric (Square D). Preventive Maintenance and Troubleshooting Guidelines for Class 9013F and 9013G Pressure Switches (Data Bulletin 9013DB0701, Dec. 2007). Accessed Oct. 8, 2026.
- HomeGuide. How Much Does a Well Pump Cost To Replace or Install? (article dated Aug. 7, 2025). Accessed Sept. 28, 2026.
We cite manufacturer documentation and public agencies first. Read how we choose and check sources.