What You Need to Know About Pool Pumps and Motors

Maintaining and Troubleshooting Swimming Pool Pumps and Motors

pool pump
A full frontal of pool equipment, including a pool pump, far left. lorjay/Pixabay

In the world of swimming pool equipment, a pool pump and motor sound like a big deal. Smart assumption. Let's find out why.

The Pump and Motor

Along with the motor, the pump draws water from a pool or spa, forcing it through the filter and heater (provided you have a heater), then returning it to the pool or spa. While they work together, a pool pump and a pool motor are two entirely different pieces of equipment. While both are elements of a pool's water circulation system, they aren't interchangeable.

What is a Pump?

A pool or spa pump consists of a housing, motor, impeller, and a strainer basket. Powered by the motor, the pump is a device that creates movement of the water. Pumps are usually known as centrifugal pumps, which cause pool water to move due to the principle of centrifugal force. Pool pumps are self-priming, which means when started up, they release all the air from the system, creating a vacuum that starts and maintains a suction. If you run a pump that has lost its prime, the motor can overheat and damage the pump.

Shopping for Pumps: What to Look For:

  • An integrated safety vacuum release system (SVRS) to detect drain blockage and automatically turn off the pump.
  • The size of the piping, suction and pressure openings influence gallons-per-minute flow rates
  • Length and terms of guarantees/warranties.
  • Noise factor: a quiet pump is a definite plus. Research to find out which pumps rate the quietest in actual hands-on reviews.
  • Energy cost savings potential. Some pumps reportedly save up to 90 percent or more compared to conventional 1- and 2-speed pumps.

What is a Pool Motor?

Often, you don't learn about your pool or spa's motor until something stops working. Let's help you troubleshoot your pool motor issue.

  • Water damage: motors can get drenched in heavy rain, when the lid is removed from the filter for cleaning, or if a pipe breaks. Give the motor a good 24 hours to air dry before starting it up, because moisture on the windings will short them out and may short out your warranty as well, according to Terry Tamminen, author of The Ultimate Guide to Pool Maintenance.
  • If the motor won't start, check the electrical supply and circuit breaker panel, looking for any loose connections of wires to the motor, advises Tamminen. "Sometimes one of the supply wires connected to the motor switch plate becomes dirty," writes Tamminen. "Similarly, if the supply wire is undersized for the load, it will overheat and melt. Check the proper wire size, replacing the supply wiring if needed. Otherwise, clean the dirt switch plate terminals and reconnect the wiring."
  • If the motor hums but won't run, either the capacitor is bad or the impeller is jammed, Tamminen encourages you to explore further. "Spin the shaft. If it won't turn freely, open the pump and clear the obstruction. If it does spin, check the capacitor." What's the best way to check a capacitor? Replace it with a new one, advises Tamminen. A white residue or liquid discharge is a sign of a bad capacitor. Another possibility for the humming motor that won't run -- your line voltage is not what it should be. Use a multimeter to test the actual voltage supply at the motor. If we've lost you at this point, summon a pool maintenance professional in your area.

    Pool and Spa Motors: FAQ

    Q: Can I replace my existing pool motor with a lower horsepower motor?

    A: Horsepower is matched with the impeller inside the pump, according to Hayward Pool Products. Having a larger impeller on a smaller horsepower motor will cause premature failure of the motor. It is better to replace it with the same horsepower.