If your taps sputter, showers weaken, or the pump won’t stop cycling, a thoughtful DIY well inspection can help you pinpoint the problem before calling a pro. With a few basic tools—a well pressure gauge, multimeter, and a safe workflow—you can often narrow down the cause to the pressure switch, pump control box, plumbing leaks, or the submersible pump itself. This guide walks you through well pump troubleshooting step by step, including electrical continuity checks, a pressure switch test, and a simple well pump reset procedure.
Start with safety
- Turn off power: Locate the well pump breaker in your main electrical panel and switch it off. Confirm it’s off with a non-contact voltage tester. Protect against contamination: Keep the well cap clean and closed unless you must open it. Don’t drop tools or debris into the casing. Know your limits: If you smell burning, see melted wires, or find water near electrical components, stop and call a licensed well contractor.
1) Identify your well system type
- Jet pump: Typically inside the home or in a pump house. More accessible for inspection. Submersible pump: Located down in the well, controlled via a pressure switch and often a pump control box (for 3‑wire pumps). Submersible pump testing is more limited without pulling the pump, but you can still check surface components and wiring.
2) Read the well pressure gauge The pressure gauge on your pressure tank tells a story.
- Normal operation: Pressure rises to the cut-out setting (e.g., 60 psi), pump stops; drops to the cut-in (e.g., 40 psi), pump starts. Symptoms to note: Pressure stuck low and pump not running: Suspect breaker tripped, failed pressure switch, control box issue, or open circuit to the pump. Pressure drops rapidly when pump stops: Possible plumbing leak, failed pressure tank bladder, or check valve failure allowing backflow. Rapid cycling (short cycling): Often a waterlogged pressure tank (bladder failure), clogged pressure switch port, or very small tank relative to demand.
3) Verify power: Is the breaker tripped?
- At the panel: Check if the pump breaker is tripped. Fully switch it OFF, then back ON. If it trips again immediately: Likely a shorted wire, motor winding fault, or water intrusion. Do not keep resetting—investigate wiring and the pump control box, or call a pro.
4) Inspect the pressure switch and do a pressure switch test Your pressure switch senses tank pressure and turns power to the pump on and off.
- Visual check: Remove the cover (power off). Look for pitted or welded contacts, insect nests, corrosion, or a clogged 1/4" nipple beneath the switch. Clean out debris and replace a severely corroded switch. Mechanical action test: Restore power briefly and watch the contacts while monitoring the well pressure gauge. At cut-in, contacts should close; at cut-out, they should open. If the gauge shows cut-in pressure but contacts do not close, the switch may be bad or sensing line clogged. Electrical continuity: Power off. Use a multimeter set to continuity or resistance. With the switch in the closed position (manually press the lever if equipped), check continuity across line-to-load terminals. You should read near-zero ohms when closed, open circuit when open. No continuity when closed indicates bad contacts; replace the switch. Safety lever: Some switches have a low-pressure cut-off lever. If the system lost prime, you may need to hold the lever to re-engage the pump during a well pump reset. Consult the switch’s label for instructions.
5) Check the pressure tank and air charge
- Waterlogged tank signs: Rapid on/off cycling, pressure swings, or a tank that feels uniformly heavy when tapped. Air charge test: Power off and drain water from the tank (open a faucet). Measure air pressure at the Schrader valve on top of the tank with a tire gauge. Set it to 2 psi below your switch cut-in (e.g., 38 psi for a 40/60 system) using an air compressor. If water comes out of the Schrader valve, the bladder is ruptured—replace the tank.
6) Examine the pump control box (for 3-wire submersible systems) A 3-wire submersible uses a surface-mounted control box with a start capacitor and relay.
- Visual inspection: With power off, open the cover. Check for bulging or leaking capacitors, burnt smell, or charred terminals. Multimeter checks: Capacitor: Discharge it safely, then measure capacitance; compare to the label. A reading far off spec means replacement. Relay: Check coil resistance and inspect contacts. Replace if burnt or failed. If the control box is defective, replacing it is often cheaper than pulling the pump.
7) Test for voltage and electrical https://martinplumbingct.com/service-area/ continuity to the pump
- Line voltage test: With the breaker on and pressure switch calling for water (contacts closed), use a multimeter to verify correct voltage at the pressure switch load side and at the control box output. No voltage at load side = bad switch or upstream issue. Voltage present but pump silent points downstream (wiring, control box, or motor). Continuity to pump: Power off, disconnect pump leads at the control box or pressure switch. Measure resistance between each pump lead pair and each lead to ground.
- Typical winding resistance values vary by horsepower and cable length but should be stable and not open. Any continuity to ground suggests a short to casing—stop and call a pro.
8) Prime and reset procedures for jet pumps
- If a jet pump lost prime: Turn power off. Remove the priming plug on the pump housing. Fill the pump and suction line completely with clean water. Replace plug, open a nearby faucet, and perform a well pump reset (restore power). The pump should build pressure and purge air. If it won’t prime, suspect suction leaks, clogged foot valve, or a blocked jet.
9) Submersible pump testing without pulling the pump
- Listen: At the wellhead, you may hear water movement in the drop pipe when the pump is running. No sound plus correct voltage may suggest a seized motor or failed impellers. Amperage draw: Use a clamp meter on the pump circuit. Compare running amps to the motor nameplate (or pump curve data). High amps may indicate a binding pump; low amps can indicate dry run or a disconnected winding. Cycle behavior: If pressure rises very slowly or never reaches cut-out, the pump may be worn, the well may be underperforming, or there’s a significant leak.
10) Rule out plumbing issues
- Whole-house shut-off test: Close the main house valve after the pressure tank. If the system now holds pressure and the pump stops cycling, the leak is in household plumbing. Check valve/backflow: If pressure bleeds down with the house valve closed, the check valve at the tank or in the drop pipe may be leaking, allowing pressure to drain back into the well.
11) When to call a professional
- Repeated breaker trips despite checks. Ground fault readings, melted insulation, or water in electrical boxes. Persistent low flow, sand or air in water, or suspected well yield problems. Need to pull a submersible pump or replace underground wiring.
Basic toolkit for DIY well inspection
- Non-contact voltage tester and multimeter Clamp meter (optional but helpful) Screwdrivers, nut drivers, small wire brush Well pressure gauge (installed on tank manifold) Tire gauge and small air compressor Flashlight and phone camera to document wiring
Quick troubleshooting roadmap
- No water at all: Check breaker tripped? Reset once. If it trips again, stop. Confirm voltage at pressure switch. If none, replace switch or fix feed. If voltage is present downstream but pump silent, inspect pump control box; test windings for electrical continuity and to ground. Low pressure or long recovery: Verify pressure tank air charge and bladder integrity. Check clogged filters/softeners. Bypass to test. Inspect pressure switch nipple for blockage. Rapid cycling: Adjust or re-pressurize tank precharge; replace bad tank if bladder failed. Ensure pressure switch differential aligns with tank size. Pump runs continuously: Look for leaks, failed check valve, low-producing well, or worn pump.
FAQs
Q1: How do I safely perform a well pump reset? A: Turn off the breaker, verify power is off, correct any observed issues, then restore power. If your pressure switch has a low-pressure cut-off lever, hold it to re-engage while watching the well pressure gauge. If the breaker trips or nothing happens, stop and troubleshoot further.
Q2: What readings should I expect when checking electrical continuity on a submersible pump? A: You should see finite resistance between motor leads (not open), with typical values depending on motor size and cable length. You should see infinite resistance from each lead to ground. Any lead-to-ground continuity indicates a fault.
Q3: How do I know if the pressure switch is the problem? A: If the gauge reaches cut-in pressure but the contacts don’t close, or there’s no continuity across closed contacts, the switch or its sensing port is faulty. Cleaning the port may help; otherwise replace the switch.
Q4: Should I replace the pump control box or the entire pump first? A: If tests show bad capacitors or relay, replace the pump control box first—it’s relatively inexpensive. If proper voltage and a good control box still don’t start the pump and windings test bad or to ground, the submersible pump likely needs replacement.
Q5: Can I perform submersible pump testing without pulling the pump? A: Yes. Use a multimeter and clamp meter to verify voltage, amperage draw, and winding continuity, inspect the control box, and observe system pressure behavior. If electrical tests or ground faults point to motor failure, you’ll need a professional to pull the pump.