Well Pump Not Working: No Water, Won't Start, or Trips Breaker — Full Diagnosis

Common Symptoms

• No water at any fixture in the home
• Pump motor runs but no water or very low pressure
• Pump will not start at all — no sound at pressure switch
• Circuit breaker for the pump trips immediately or after a few minutes
• Pressure gauge reads 0 PSI and never builds up
• Pressure gauge drops rapidly and pump cycles every few seconds
• Water had to be restored after well service and never came back

Most Likely Causes

1. 1

   Failed Pressure Switch — Contact Pitting or Blocked Port (Most Common)

   The pressure switch (typically Square D 9013FSG2, rated for 30/50 PSI or 40/60 PSI) senses system water pressure and turns the pump on when pressure drops to the cut-in set point. Two failure modes: (1) Pitted or burned contacts — the contacts arc every time the pump cycles; after years of use they pit and fail to make contact, preventing the pump from starting. You'll see black burn marks on the contact faces inside the switch. (2) Blocked pressure port — a tiny port at the base of the switch connects to the water line; spider webs, mineral scale, or debris clog this port so the switch never senses pressure drop and doesn't signal the pump to start. Manual lever test: most Square D switches have a small lever that manually closes the contacts — briefly flipping it while the system is pressurized (and the breaker is on) tells you whether the pump runs when given a direct signal. If the pump runs with the lever but not automatically, replace the switch ($15–$25).

2. 2

   Failed Run Capacitor (Jet Pumps Only)

   Single-phase jet pumps (Goulds J5S, Myers HJ100S, Flotec FP4012) use a run capacitor to start and run the motor. The capacitor stores an electrical charge that gives the motor its starting torque. When it fails, the motor hums but won't spin, or won't start at all. Capacitor test: disconnect power, discharge the capacitor by briefly shorting its terminals with an insulated screwdriver, then test in capacitance mode on a multimeter. Compare the measured µF (microfarads) to the rating printed on the capacitor's nameplate — a working capacitor should be within ±5% of its rating. A reading of 0 or significantly below rating = failed capacitor, replace with an identical CBB60 replacement capacitor matching the µF and voltage rating ($8–$20). Never test a charged capacitor — it can deliver a dangerous shock.

3. 3

   240V Submersible Pump — 3-Wire vs. 2-Wire Wiring and Control Box

   Submersible well pumps (Goulds 10GS15, Franklin Electric series) come in two wiring configurations: 3-wire and 2-wire. 3-wire pumps: the motor has three conductors plus ground (black/red/yellow + green); the run capacitor and start relay are housed in a separate above-ground control box (Franklin Electric 2823028910 is the industry standard for 1/2–1 HP pumps). 2-wire pumps: the capacitor is built into the motor itself and there is no separate control box — just two conductors plus ground. If a 3-wire pump has a failed control box, the pump won't start — replace the Franklin Electric control box rather than pulling the pump from the well. The control box failure is the most common submersible issue after the pressure switch: a failed start capacitor or relay inside the control box prevents startup; replacement boxes cost $40–$120 depending on HP rating.

4. 4

   No Water After Well Service — Torque Arrestor and Pitless Adapter

   If water stopped after the pump was pulled and reinstalled (for service), two mechanical causes are common: (1) Torque arrestor misaligned — a torque arrestor is a rubber device clamped to the pump drop pipe to prevent the pump from spinning against the casing. If it's positioned incorrectly or too large for the casing, it can wedge the pump against the well casing wall, blocking the pump intake. (2) Pitless adapter failure — the pitless adapter is a threaded or pushed fitting where the horizontal service line exits the well casing. If it wasn't fully seated during reinstallation, water flows down into the well instead of to the house. Both issues require pulling the pump again.

5. 5

   Pump Running But No Pressure — Check Valve Failure

   Submersible pumps have a check valve at the pump head (at the bottom of the drop pipe) that holds water in the pipe column when the pump is off. If this check valve fails, the water column drains back into the well each time the pump stops — when the pump starts again it must re-prime the entire column before pressure builds, causing a long delay or no pressure at all. Diagnosis: turn on a tap and watch the pressure gauge. If the gauge goes to 0 when the pump stops and takes very long to build, the check valve has failed. Check valve replacement ($15–$40) requires pulling the submersible pump — typically a contractor job. Also verify: some systems have an additional check valve at the pressure tank tee; test this with a 1-way flow test (water should flow only one direction).

6. 6

   Breaker Trips — Worn Motor Bearings or Ground Fault

   A well pump breaker that trips immediately or within minutes typically indicates: (1) Worn motor bearings — when bearings wear, the motor draws locked rotor amps (5–10× normal running current), tripping the 2-pole 240V breaker immediately. (2) Ground fault — damaged motor winding insulation allows current to flow to ground, tripping a breaker or GFCI. Megohm test for submersible motors: disconnect the motor leads at the control box or pressure switch, set a multimeter to its highest resistance range (or use a megohmmeter), and measure resistance from each motor lead to ground. A reading ≥1 MΩ (1,000,000 ohms) is acceptable; below 1 MΩ indicates insulation breakdown and the motor should be replaced. This test can be performed at the surface without pulling the pump.

Quick DIY Checks

1. 1Check the breaker first: at the main electrical panel, locate the 240V double-pole breaker for the well pump (usually labeled 'Well Pump' or 'Water Pump', 20A or 30A). If it's tripped (center position), reset it fully to OFF then back ON. If it trips immediately, the motor has a ground fault — do not reset again. If it holds, proceed to the pressure switch.
2. 2Inspect the pressure switch (Square D 9013FSG2 or similar, mounted on the pressure tank or pump): remove the cover (one screw or snap-off). Look for black burn marks on the contact faces — pitting means the contacts need replacement or the switch needs replacement ($15–$25). Check the small port at the bottom of the switch housing for mineral scale, spider webs, or debris — clear with a toothpick and compressed air. With the cover OFF and power ON (careful of live 240V terminals), briefly flip the manual lever on the switch — if the pump starts and pressure builds, the switch itself is the problem.
3. 3Test the jet pump run capacitor (jet pumps only): turn OFF the breaker. Locate the capacitor (a cylindrical component on or inside the pump motor housing). Discharge it: briefly short its terminals with an insulated screwdriver to eliminate stored charge. Set multimeter to capacitance (µF) mode. Probe the capacitor terminals. Compare to the nameplate µF rating — should be within ±5%. A reading of 0 or <80% of rated value = replace with a CBB60 matching the µF and voltage rating.

1. 4Check the Franklin Electric control box (3-wire submersible only): the control box is mounted on the wall near the pressure tank. Remove the cover. Look for burn marks on the start relay or capacitor inside. Listen: when the pump should start (pressure is low, switch calls for pump), you should hear a relay click in the control box. No click = relay failed. Visible burn marks on the capacitor = capacitor failed. Franklin Electric replacement boxes (2823028910 for 1/2–1 HP) are available at plumbing supply houses — replace the entire box rather than individual components.
2. 5Perform a megohm test on a submersible pump that trips its breaker: turn OFF the breaker and disconnect the motor leads at the control box or pressure switch terminal. Set multimeter to its highest resistance range (usually 20MΩ or 'Ω' max). Probe each motor lead (black, red, yellow for 3-wire; black, red for 2-wire) to the ground wire one at a time. Reading ≥1 MΩ = insulation is acceptable. Reading <1 MΩ = insulation has broken down and the pump motor must be replaced. Document readings — well contractors will want this data.
3. 6Diagnose a failed check valve: turn on a fixture and note the pressure gauge. When the pump stops, watch how fast pressure falls. If the gauge drops to 0 within seconds of the pump stopping and the pump takes more than 30–60 seconds to build pressure again, the submersible check valve at the pump head has likely failed. Also check the check valve at the pressure tank tee (if present) — remove it and test for one-way flow by blowing through it from both sides. A failed check valve at the pressure tank level is DIY-replaceable; one at the pump head requires pulling the pump.

Repair vs Replace

Recommended Tools & Parts

• Square D 9013FSG2 Pressure Switch (30/50 PSI)

  Industry-standard well pump pressure switch with manual lever. Cuts pump in at 30 PSI, cuts out at 50 PSI. Fits most 1/4-inch NPT pressure tank ports. Includes low-pressure cutoff to protect pump if well runs dry.

  $15–$25

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• Square D 9013FHG Pressure Switch (40/60 PSI)

  Well pump pressure switch set for 40/60 PSI cut-in/cut-out. Better for homes with higher pressure needs or two-story buildings. Same installation as 9013FSG2.

  $18–$28

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• Franklin Electric 2823028910 Control Box (1/2–1 HP, 230V)

  OEM replacement control box for 3-wire Franklin Electric submersible well pumps, 1/2–1 HP, 230V. Contains start capacitor and relay. Replace entire box rather than individual components for reliability.

  $50–$120

  Buy on Amazon →

• CBB60 Run Capacitor (Jet Pump Replacement)

  Round AC motor run capacitor for jet pump motors. Select µF and voltage rating matching the nameplate on your existing capacitor. CBB60 type is the standard for residential water pump motors.

  $8–$20

  Buy on Amazon →

• Well Pump Check Valve (Brass, 1-1/4 in.)

  Brass inline check valve for well pump discharge line. Prevents water column from draining back when pump stops. Install at pressure tank tee. Size must match your pump discharge pipe diameter.

  $15–$35

  Buy on Amazon →

• Digital Multimeter with Capacitance Mode

  Multimeter with capacitance (µF) and high-resistance mode for testing jet pump capacitors and submersible motor insulation (megohm test). Required for accurate well pump diagnosis.

  $25–$60

  Buy on Amazon →

Links are Amazon affiliate links (tag: fixitfastai-20). Prices are estimates.

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