Pool Pumps and Circulation

Applies to: In-ground and above-ground home pools; permanently installed pumps and the filter pumps sold with storable above-ground pools; single-speed, two-speed and variable-speed pumps

What circulation does

ENERGY STAR describes the pool pump as the part that re-circulates water through a filter to keep the water clear and hygienic. Hayward's manual for its ProSeries sand filters adds that clear water takes two things together: adequate filtration and proper water chemistry.^[1][3]

A U.S. Department of Energy guide notes the pump may also backwash the filter, run a chlorinator, feed a cleaner, or move water through a heater or solar panel.^[4]

Run time depends on your pool. Hayward's ProSeries sand filter manual says continuous operation is not necessary for most pools, but to filter long enough each day for at least one complete turnover, which ENERGY STAR defines as circulating a volume of water equal to the pool's volume.^[3][5]

Single-speed, two-speed and variable-speed pumps

• Single-speed: ENERGY STAR says one-speed pumps are set to run at the higher speeds a pool cleaner needs, even though filtration needs only half that flow. DOE's guide adds that they cannot change their flow rate, so they are sized for the most demanding task.^[1][4]
• Two-speed: DOE's guide notes that with only two speed choices, it is much harder to fine-tune flow for the best energy savings.^[4]
• Variable-speed: ENERGY STAR says these pumps can run at a wide range of speed settings, and your installer sets the speed that is right for your pool.^[6]

ENERGY STAR says variable-speed and multi-speed pumps can help cut energy costs, and slower circulation puts less strain on filters and plumbing. It warns that an oversized pump pushes water too fast for the filter to work well.^[1][6]

Storable above-ground pools often use integral pumps, with the sand or cartridge filter built into the pump housing; ENERGY STAR's pump specification does not cover them. Hayward says its pumps are for permanently installed pools, not storable ones, while Bestway says one of its sand filter pumps is for storable pools only. Match any replacement to your pool type.^[3][5][7]

Strainer basket and priming

ENERGY STAR advises clearing debris from the strainer baskets in the pump and skimmer regularly so water flow is not hampered.^[1]

Hayward's Super Pump manual gives this order for opening the strainer. Your pump may differ, so use your own manual:^[2]

1. Stop the pump and turn off its power before you open anything. Hayward says to turn off power before working on the pump or motor.^[2]
2. Close the valves in the suction and outlet pipes.^[2]
3. Release all pressure using the filter's manual air relief valve.^[2]
4. Clean the basket without striking it, and check the cover gasket.^[2]
5. Refill the strainer housing with water, tighten the cover knobs by hand only, and reopen the valves before restarting. Hayward's SwimClear filter manual says all suction and discharge valves must be open when starting the system, and to stand clear of the filter.^[2][8]

Hayward says its in-ground pumps are self-priming: the pump housing must be full of water to create the vacuum that draws water from the pool. If a pump will not prime, Hayward points first to a suction-side air leak or a blocked suction line, and says to stop the motor and find the cause if priming takes longer than its manual allows.^[2][9][10]

Electrical safety around the pump

Hayward says the GFCI should be tested on a routine basis, and Bestway's manual for an above-ground pump with a built-in GFCI says to test it before each use. Bestway describes the test this way:^[2][7]

1. Push the test button. The GFCI should cut power.^[7]
2. Push the reset button. Power should come back.^[7]
3. If it fails the test, or if the GFCI cuts power on its own without the test button being pushed, Bestway says a ground current may be flowing, which means a possible electric shock. Do not use the pump. Disconnect it and have a qualified service representative fix the problem first.^[7]

• Bestway says not to touch the plug with wet hands and to replace a damaged cord immediately.^[7]
• Hayward says to keep motor air vents clear and not to hose off the motor with water.^[2]
• Hayward's FAQ says to keep plants off the motor, since air circulation is crucial, and to place the pump where it drains well.^[12][13]

Pumps at closing time and in freezing weather

Closing steps depend on your climate and equipment. Hayward's Super Pump manual says to drain all water from the pump and piping when freezing temperatures are expected, turning power off first, and notes that letting the pump freeze with water in it voids the warranty. It also warns never to purge the system with compressed air.^[2]

For the rest of your closing routine, use your own manuals and our pool closing checklist.

When to call a professional

For drowning-prevention layers such as fences, alarms and supervision, see our backyard pool safety pages.