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Swimming Pool Pump Troubleshooting

  • Pump will not prime — to much air
    • Check suction piping and valve glands on any suction gate valves.
    • Secure lid on pump strainer pot and make sure lid gasket is in place.
    • Check water level to make sure skimmer is not drawing air.
  • Pump will not prime — not enough water
    • Make sure suction lines, pump strainer, and pump volute are full of water.
    • Make sure valve on suction line is working and open, (some systems do not have valves).
    • Check water level to make sure water is available through skimmer.
  • Pump strainer clogged
    • Clean pump strainer pot.
  • Pump strainer gasket defective
    • Replace gasket.
  • Air pockets or leaks in suction line
    • Check suction piping and valve glands on any suction gate valves.
  • Pump Will Not Prime — to much air
    • Secure lid on pump strainer pot and make sure lid gasket is in place.
    • Check water level to make sure skimmer is not drawing air.
  • Clogged impeller
    • Turn off electrical power to the pump.
    • Remove the clamp that holds the volute to the seal plate.
    • Slide the motor and seal plate away from the volute.
    • Clean debris from impeller.
      • If debris cannot be removed, complete the following steps.
      • Remove left hand thread anti-spin bolt and O-ring.
      • Remove, clean and reinstall impeller.
      • Reinstall anti-spin bolt.
    • Reinstall diffuser and quad ring.
    • Reinstall motor and seal plate into volute.
    • Reinstall clamp around seal plate and volute and tighten securely.
  • Pump strainer clogged
    • Clean suction trap.
  • Improper or loose wiring connections; open switches or relays; tripped circuit breakers, GFCI’s, or blown fuses.
    • Check all connections, circuit breakers, and fuses.
    • Reset tripped breakers or replace blown fuses.
    • Terminal board connection must agree with the wiring diagram on motor data plate label.
    • Motor must be wired for the same voltage as the supply voltage.
    • Manually check rotation of motor shaft for free movement and lack of obstruction.
    • If you have a timer, be certain it is working properly. Bypass it if necessary.
  • Low voltage at motor or power drop (frequently caused by undersized wiring or extension cord use).
    • Contact qualified professional to check that the wiring gauge is heavy enough.
  • Pump motor is equipped with an “automatic thermal overload protector.”
    • The motor will automatically shut off if power supply drops before heat damage can build up causing windings to burn out.
    • The “thermal overload protector” will allow the motor to automatically restart once the motor has cooled. It will continue to cut On/Off until the problem is corrected.
    • Be sure to correct cause of overheating.
  • Impeller jammed with debris. Open the pump and remove the debris.
  • Defective wiring
  • Defective capacitor
  • Defective or unadjusted centrifugal switch
  • Empty pump/strainer housing.
    • Make sure pump/strainer housing is filled with water and cover o-ring is clean.
    • Ensure o-ring is properly seated in the cover o-ring groove.
    • Ensure o-ring is lubricated with “Jack’s 327” and that strainer cover is locked firmly in position.
    • Lubricant will help to create a tighter seal.
  • Loose connections on suction side.
    • Tighten pipe/union connections.
    • Any self-priming pump will not prime if there are suction air leaks.
    • Leaks will result in bubbles emanating from return fittings on pool wall.
  • Leaking O-ring or packing glands on valves.
    • Tighten, repair, or replace valves.
  • Strainer basket or skimmer basket loaded with debris.
    • Remove strainer housing cover or skimmer cover, clean basket, and refill strainer housing with water. Tighten cover.
  • Suction side clogged.
    • Contact a qualified repair professional.
    • Block off to determine if pump will develop a vacuum. You should have 5”-6” of vacuum at the strainer cover (Only your pool dealer can confirm this with a vacuum gauge).
    • You may be able to check by removing the skimmer basket and holding your hand over the bottom port with skimmer full and pump running. If no suction is felt, check for line blockage.
      • If pump develops a vacuum, check for blocked suction line or dirty strainer basket. An air leak in the suction piping may be the cause.
      • If pump does not develop a vacuum and pump has sufficient “priming water”:
        • Re-check strainer housing cover and all threaded connections for suction leaks. Check if all system hose clamps are tight.
        • Check voltage to ensure that the motor is rotating at full RPM’s.
        • Open housing cover and check for clogging or obstruction in suction. Check impeller for debris.
        • Remove and replace shaft seal only if it is leaking.
  • Air leak in suction piping, cavitations caused by restricted or undersized suction line or leak at any joint, low water level in pool, and unrestricted discharge return lines.
    • Correct suction condition or throttle return lines, if practical.
    • Holding hand over return fitting will sometimes prove this point or putting in a smaller eyeball fitting.
  • Vibration due to improper mounting, etc.
    • Mount the pump on a level surface and secure the pump to the equipment pad.
  • Foreign matter in pump housing. Loose stones/debris hitting impeller could be cause.
    • Clean the pump housing.
  • Motor bearings noisy from normal wear, rust, overheating, or concentration of chemicals causing seal damage which will allow chlorinated water to seep into bearings wiping out the grease causing bearing to whine.
    • All seal leaks should be replaced at once.

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