Shallow Well Pump Not Working – Troubleshooting Guide
| Symptom | Most Likely Cause | DIY Difficulty |
|---|---|---|
| No water, pump silent | Tripped breaker or failed pressure switch | Easy |
| No water, pump runs | Lost prime, low water level, or clogged foot valve | Moderate |
| Pump runs but low pressure | Waterlogged pressure tank or worn impeller | Moderate |
| Pump cycles rapidly (short cycling) | Waterlogged pressure tank (lost air charge) | Easy–Moderate |
| Pump won’t shut off | Pressure switch stuck or set too high | Easy |
| Pump trips breaker repeatedly | Seized motor or wiring short | Moderate–Hard |
1. Check the Power Supply (Start Here)
A tripped circuit breaker or a blown fuse is the single most common reason a shallow well pump stops working — and the easiest to fix. Always rule out power before opening anything else.
- Go to your electrical panel and find the breaker labeled for the well pump. If it is tripped (in the middle or “off” position), flip it fully off, then back on.
- If the breaker trips again immediately, do not reset it a third time — skip to Cause 5 (motor/wiring issue).
- Check that the voltage at the pump disconnect box matches the pump’s nameplate rating (typically 115 V or 230 V). Use a multimeter set to AC voltage.
- Inspect the wiring from the panel to the pump for visible damage, rodent chewing, or loose connections at terminal blocks. Tighten any loose screws.
2. Inspect and Test the Pressure Switch
The pressure switch tells the pump when to turn on and off; a corroded, burned, or misadjusted switch will prevent the pump from starting even when power is present. This is the second most common failure point.
- Turn off the pump breaker before opening the pressure switch cover.
- Remove the cover and look for burned or pitted electrical contacts and corrosion on the terminals. Any black scorching means the switch needs replacement.
- With power restored, use a multimeter set to AC voltage to confirm that voltage is reaching the switch’s input terminals when the pump is supposed to be running.
- Check the cut-in and cut-out pressure settings (typically 20/40 psi or 30/50 psi). A small adjustment nut on the large spring raises or lowers both settings — consult the label inside the switch cover for guidance.
- If the contacts are burned or the switch will not hold its settings, replace the pressure switch.
A well pump pressure switch is an inexpensive and straightforward DIY replacement (typically $15–$40).
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3. Re-Prime the Pump
Shallow well pumps are self-contained above-ground units that rely on a column of water to create suction; if air enters the intake line — due to a dry period, a cracked fitting, or a leaky foot valve — the pump loses prime and will run without moving any water.
- Turn the pump off at the breaker.
- Locate the priming plug on top of the pump housing (a square-headed plug or a cap marked “prime”).
- Remove the plug and slowly pour clean water into the housing until it is completely full and water begins to overflow from the opening.
- Reinstall the plug hand-tight, then restore power and start the pump. Water should flow within 30–60 seconds.
- If the pump loses prime again quickly, there is an air leak — inspect all suction-side fittings, the inlet pipe, and the foot valve at the bottom of the drop pipe for cracks or loose connections.
- If the foot valve is allowing water to drain back, replace it.
A foot valve prevents water from draining back out of the suction pipe, maintaining the pump’s prime.
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4. Check and Recharge the Pressure Tank
A waterlogged pressure tank — one that has lost its air charge — causes rapid short-cycling that stresses the pump motor and can eventually cause it to overheat and fail. It can also produce weak, pulsing water pressure.
- Turn off the pump at the breaker and open a nearby faucet to release all pressure from the tank.
- Locate the Schrader valve (similar to a tire valve) on the top or side of the tank.
- Using a tire pressure gauge, check the air charge. It should read approximately 2 psi below the cut-in pressure of your pressure switch (e.g., 28 psi for a 30/50 switch).
- If the pressure is low, add air with a standard bicycle or compressor pump until it reaches the correct pre-charge level.
- If water squirts out of the Schrader valve when you depress the pin, the tank’s internal bladder or diaphragm has ruptured — the tank must be replaced.
A replacement bladder-type pressure tank typically costs $60–$200 depending on size (2–20+ gallons).
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5. Inspect the Pump Motor and Capacitor
If power and controls check out but the pump hums without running, or trips the breaker, the start capacitor — a small cylindrical component on the motor — may have failed, or the motor itself may be seized or burned out.
- Turn off the breaker. A humming pump that won’t spin is a warning that the motor is trying to start and failing — do not let it run this way for more than a few seconds, as it will overheat.
- Locate the capacitor on the motor housing. It is typically a cylindrical or oval-shaped component held by a metal strap.
- Look for visible signs of failure: a bulged top, burn marks, or oily residue leaking from the capacitor body.
- A capacitor can be tested with a multimeter that has a capacitance (µF) function — compare the reading to the value printed on the capacitor label. A reading significantly below spec means the capacitor is bad.
- Replace the capacitor with one matching the exact microfarad (µF) and voltage rating. Capacitors store a lethal charge — discharge before handling by shorting the two terminals through a 20,000-ohm resistor.
- If replacing the capacitor does not fix the problem and the motor shaft cannot be turned by hand, the motor is seized and the pump assembly will need to be replaced.
Match the µF and voltage rating printed on the original. Capacitors are typically $8–$25.
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6. Examine the Inlet Screen and Check Valve for Clogs
Sediment, mineral scale, or debris can partially or fully clog the pump’s inlet strainer or the check valve on the discharge side, causing reduced flow or a complete loss of water delivery even when the pump runs normally.
- Turn off the pump at the breaker and relieve all line pressure by opening a faucet.
- Disconnect the inlet (suction) pipe from the pump. Inspect the inlet screen or strainer for sediment, iron deposits, or debris. Clean it with a soft brush under running water or replace it if it is damaged.
- Locate the check valve on the discharge side of the pump (between the pump and the pressure tank). A failed check valve that sticks closed will prevent any water from reaching the tank; one that sticks open can cause prime loss.
- To test the check valve, remove it and manually push the internal flap with a screwdriver — it should move freely and spring back. Replace it if it is stiff, corroded, or broken.
- Reinstall all components, reprime the pump (see Cause 3), and restore power.
Choose a check valve matching your pipe diameter (commonly ¾” or 1″). Prices range from $8–$30.
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Frequently asked questions
How do I know if my shallow well pump needs replacing instead of repairing?
If the motor is burned out, the pump housing is cracked, or the cost of parts exceeds roughly 50% of a new pump’s price, replacement is generally the better investment. Pumps over 10–15 years old with repeated failures are also strong replacement candidates. A new shallow well pump typically costs $150–$400 for the unit, plus installation labor if needed.
Why does my shallow well pump keep losing prime?
Repeated prime loss almost always indicates an air leak somewhere on the suction side — common culprits include a cracked inlet pipe, a loose threaded fitting, a worn pump seal, or a leaking foot valve at the bottom of the drop pipe. Inspect every joint and fitting from the pump inlet all the way down to the foot valve, and replace any component that shows cracking, corrosion, or failed thread sealant.
What is the maximum depth a shallow well pump can handle?
A standard shallow well jet pump can lift water from a maximum depth of approximately 25 feet (about 7.6 meters) below the pump. This is a physical limit imposed by atmospheric pressure, not pump quality. If your water table is deeper than 25 feet, you will need a deep well jet pump or a submersible pump instead. For more guidance, see the EPA’s Private Drinking Water Wells resource.
Is shallow well pump troubleshooting safe to do myself?
Most diagnostic steps — checking the breaker, inspecting the pressure switch, repriming, and checking tank pressure — are safe for a careful DIYer. Always turn off the breaker and confirm power is off with a non-contact voltage tester before touching any wiring or opening any electrical enclosure. Work involving motor capacitors requires extra caution because capacitors retain lethal voltage after the power is off. If you are uncomfortable working with electricity or are unsure of a diagnosis, hire a licensed well pump technician.