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Submersible Well Pump Troubleshooting

This “TROUBLESHOOTING” information is intended to guide in the general determination of pump problems and their solutions. Be sure to thoroughly read the owner's manual and warranty. The technical information provided in the and sites is for educational purposes only.Technically qualified personnel should install pumps and motors. We recommend that a licensed contractor install all new systems and replace existing pumps and motors. Failure to install in compliance with local and national codes and manufacturers recommendations may result in electrical shock, fire hazard, unsatisfactory performance, and equipment failure.

WARNING: Unplug pump from power source before handling. Failure to do so could result in severe personal injury or death when touching the pump or discharge piping.

Motor Does Not Start

  • No power or incorrect voltage: Check voltage at line terminals. The voltage must be ± 10% of rated voltage. Contact Power Company if voltage is incorrect.
  • Fuses blown or circuit breakers tripped: Check fuses for recommended size and check for loose, dirty or corroded connections in fuse receptacle. Check for tripped circuit breakers. Replace with proper fuse or reset circuit breakers
  • Defective pressure switch: Check voltage at contact points. Improper contact of switch points can cause voltage less than line voltage. Replace pressure switch or clean points
  • Control box malfunction: Repair or replace.
  • Defective wiring Check for loose or corroded connections or defective wiring: Correct faulty wiring or connections.
  • Bound pump: Check for misalignment between pump and motor or a sand bound pump. Amp readings will be 3 to 6 times higher than normal until the overload trips. Pull pump and correct problem. Run new installation until the water clears.
  • Defective cable or motor: Repair or replace.

Motor Starts Too Often

  • Pressure switch: Check setting on pressure switch and examine for defects. Reset limit or replace switch.
  • Check valve - stuck open: Damaged or defective check valve will not hold pressure. Replace if defective.
  • Waterlogged tank: Check air charge. Repair or replace.
  • Leak in system: Check system for leaks. Replace damaged pipes or repair leaks. Possible Cause Checking Procedures Corrective Action

Motor Runs Continuously

  • Pressure switch: Check switch for welded contacts. Check switch adjustments. Clean contacts, replace switch, or adjust setting.
  • Low water level in well: Pump may exceed well capacity. Shut off pump, wait for well to recover. Check static and drawdown level from well head. Throttle pump output or reset pump to lower level. Do not lower if sand may clog pump.
  • Leak in system: Check system for leaks. Replace damaged pipes or repair leaks.
  • Worn pump: Symptoms of worn pump are similar to those of drop pipe leak or low water level in well. Reduce pressure switch setting, if pump shuts off worn parts may be the fault. Pull pump and replace worn parts.
  • Loose coupling or broken motor shaft: Check for loose coupling or damaged shaft. Replace worn or damaged parts.
  • Pump screen blocked: Check for clogged intake screen. Clean screen and reset pump depth.
  • Check valve stuck closed: Check operation of check valve. Replace if defective.
  • Control box malfunction: Repair or replace

Motor Runs But Overload Protector Trips

  • Incorrect voltage: Using voltmeter, check the line terminals: Voltage must be within ± 10% of rated voltage. Contact Power Company if voltage is incorrect.
  • Overheated protectors: Direct sunlight or other heat source can raise control box temperature causing protectors to trip. The box must not be hot to touch. Shade box, provide ventilation or move box away from source.
  • Defective control box: Repair or replace.
  • Defective motor or cable: Repair or replace.
  • Worn pump or motor: Check running current. Replace pump and/or motor.

Little Or No Liquid Delivered By Pump

  • Faulty or incorrectly installed check valve: Inspect check valve and repair as required.
  • Pump air Bound: Successively start and stop pump until flow is delivered.
  • Lift too high for pump: Review unit performance chart
  • Pump bound by foreign matter: Pull pump, clean, adjust set depth as required.
  • Pump not fully submerged: Check well recovery, lower pump if possible.
  • Well contains excessive amount of air of gases: If successive starts and stops does not remedy, well contains excessive air or gases. Consult a well driller.
  • Excessive pump wear: Pull pump and repair or replace as required.
  • Incorrect motor rotation(three phase only): Reverse any two motor electrical leads.


  • Incorrect air charge in tank (Set air-charge 2 PSI below the pump cut-in pressure for steel bladder tanks or 4 PSI for fiberglass bladder tanks).
  • Bladder or diaphragm has ruptured. (Check by depressing the air valve stem. If water emerges, diaphragm is ruptured (Replace tank).)
  • Incorrect pressure switch differential (Adjust pressure switch differential to 20 PSI. Tank too small. Check tank sizing, (Replace tank).
  • Pressure tanks are usually pre-charged at 30 PSI.
  • Drain water from tank to check tank air charge.
  • Pressure switches are usually set for 30-50 PSI.


  • Faulty check or foot valve. (Close valve between tank and house. If gauge pressure drops, the check or foot valve is faulty. Replace defective valve)
  • Slow leak in house plumbing. (Close valve between tank and house. If gauge pressure does not drop, there is a slow leak in the house plumbing. Repair leak)


  • Defective air valve core. (Brush soapy water around air stem. If leak is found, the valve core is defective. Replace valve core)
  • Defective tank weld. (Brush soapy water around tank welds. If leak is found, the tank is defective. Replace tank)
  • Ruptured tank diaphragm Replace tank


  • Incorrect air charge in tank Set air-charge 2 PSI below the pump cut-in pressure for steel bladder tanks or 4 PSI for fiberglass bladder tanks
  • Defective pump Repair pump
  • Defective well piping Repair or replace piping


  • Incorrect air charge in tank (Set air-charge 2 PSI below the pump cut-in pressure for steel bladder tanks or 4 PSI below for fiberglass bladder tanks )
  • Diaphragm Stuck. )If air charge is 2 PSI below cut-in, relieve all air from tank. Run pump through one cycle. If tank fills, diaphragm was stuck. Reset air charge)
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