Well Pump Running Continuously: Troubleshooting and Repair
A well pump that runs without cycling off represents one of the most consequential failure modes in private water supply systems, combining mechanical wear acceleration, elevated energy consumption, and potential total pump burnout within hours. This page covers the technical definition of continuous pump operation, the system components involved, the failure scenarios that produce this symptom, and the decision thresholds that separate owner-serviceable conditions from licensed contractor work. The scope is national, applicable across residential and light commercial well systems throughout the United States.
Definition and scope
Continuous pump operation — colloquially called "pump run-on" — describes a condition in which a submersible or jet well pump fails to shut off after reaching the pressure tank's cut-off setpoint. Under normal operation, a pressure switch cuts power to the pump when system pressure reaches the upper limit (typically 50 or 60 PSI in residential systems), and restores power when pressure drops to the lower limit (typically 30 or 40 PSI). When the pump runs without interruption, this switching cycle has broken down at one or more points in the system.
The condition is distinct from short-cycling, which involves rapid on-off switching caused by a waterlogged pressure tank. Continuous operation means the pump never reaches cut-off, or the cut-off mechanism is non-functional. The practical risk is motor burnout: most residential submersible pump motors are not rated for continuous duty, and sustained operation can destroy a motor within 2 to 8 hours depending on load and ambient ground temperature.
Well pump systems fall under jurisdiction of state well construction programs administered at the state level, with model standards established by the National Ground Water Association (NGWA) and incorporated into state codes across the US. Electrical installation of pump systems is governed by NFPA 70 (National Electrical Code), enforced through local Authority Having Jurisdiction (AHJ) inspectors.
How it works
A standard residential well pump pressure system consists of four interdependent components: the pump motor (submersible or jet), the pressure tank, the pressure switch, and the supply piping. The wellpump-repair-provider network-purpose-and-scope section of this resource describes how qualified contractors are categorized by the type of system they service.
The pressure tank contains an air bladder or air charge that maintains system pressure between pump cycles. When water is drawn, pressure drops until the switch triggers the pump. The pump charges the tank until cut-off pressure is reached and the switch opens the circuit. Three primary control points can fail to produce continuous run-on:
- Pressure switch failure — The switch contacts may weld closed due to arcing, preventing the circuit from opening at cut-off pressure.
- Pressure tank failure — A ruptured bladder or depleted air charge causes the tank to fill entirely with water, eliminating the air cushion and preventing adequate pressure buildup.
- System leak or demand exceeding pump capacity — A significant leak downstream (broken pipe, open valve, failing fixture) draws water faster than the pump can deliver, holding pressure permanently below cut-off.
A fourth scenario — pump wear reducing output — can mimic continuous run conditions when a worn impeller can no longer generate sufficient pressure to reach the cut-off setpoint.
Common scenarios
The four scenarios above manifest differently depending on system age, water quality, and installation type:
- Failed pressure switch (closed contacts): The switch will not open regardless of system pressure. Testing with a multimeter across switch terminals confirms zero resistance when pressure exceeds cut-off. This is an electrical component failure requiring switch replacement — typically a 30-minute repair for a licensed pump technician.
- Waterlogged pressure tank: The tank feels heavy when tapped at the bottom and produces a dull rather than hollow sound. Air pre-charge in a bladder-type tank should measure 2 PSI below the cut-in pressure setpoint (per Amtrol Well-X-Trol installation standards, a widely referenced industry specification). A depleted air charge can sometimes be corrected by adding air through the Schrader valve, but a ruptured bladder requires full tank replacement.
- Downstream leak: System pressure does not build during pump operation. Isolating sections of supply piping and monitoring pressure behavior identifies the breach location. Leak repair may fall under plumbing permits required by local jurisdiction.
- Worn pump impeller: Pump runs but output flow is reduced. A pump performance test comparing delivered GPM against the pump's rated curve (found in manufacturer documentation) quantifies degradation. Impeller replacement or full pump replacement is typically required.
For access to licensed contractors structured by service type and region, the wellpump-repair-providers section catalogs professionals by the categories described above.
Decision boundaries
Not all continuous-run conditions require the same level of intervention. The following classification separates severity levels:
| Condition | Owner-Serviceable | Licensed Contractor Required |
|---|---|---|
| Adding air to pressure tank Schrader valve | Yes | No |
| Replacing pressure switch | Jurisdiction-dependent | In most states, yes |
| Replacing pressure tank | No — pressurized system | Yes |
| Pulling and replacing submersible pump | No — confined space, electrical | Yes |
| Repairing supply line leak (below grade) | No — may require permit | Yes |
Submersible pump replacement specifically involves confined space access to the well casing, high-voltage electrical disconnection, and in most states, a licensed well contractor or pump installer credential issued by the state groundwater regulatory agency. The how-to-use-this-wellpump-repair-resource page describes how contractor qualification categories map to these repair types.
Permit requirements for pump repair and replacement vary by state. States including California, Florida, and Texas require well contractor licensing through dedicated groundwater programs. Work on potable water systems in most jurisdictions triggers inspection by the local AHJ under state plumbing codes that reference NFPA 70 for electrical components and state-adopted versions of the Uniform Plumbing Code (UPC) or International Plumbing Code (IPC) for water supply components.