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How to Winterize a Pool Pump and Filter

Drain the pump and filter, leave the plugs out and store cartridges or grids frost-free. Hayward and Pentair steps for sand, cartridge and DE filters.

October 16, 2026•PoolSpaKit Editorial
Pool pump and sand filter being drained for winter

To winterize a pool pump and filter, turn the power off, drain all the water out of both, leave the drain plugs out, and store the parts that hold water (cartridges or grids, and on some setups the pump itself) somewhere that won’t freeze. The manuals agree on that much. They differ on the details: how many plugs, where the plugs go, and what to do with the valve. Use the steps for your brand below.

Closing for a short cold snap only? Pentair’s cartridge-filter guide says that in milder climates, when temporary freezing conditions may occur, ensure the filtration system operates continuously until the freeze has passed, and its SuperFlo pump guide says to run your filtering equipment all night. Full winterizing is for a pool that will sit closed. Pentair puts it this way: if prolonged freezing conditions are expected, the filter should be fully drained and cartridges should be removed.

Two warnings before you open anything

  • Power off first. Shut off electrical power for the pump at the circuit breaker (Pentair). Hayward says to turn OFF power to motor before draining pump.
  • Do not purge the system with compressed air. Hayward warns that purging the system with compressed air can cause components to explode, and allows only a low pressure (below 5 PSI), high volume blower for the pump, filter or piping. Pentair adds that trapped air can launch the lid with deadly force, so if any air is used, make sure the filter air relief valve is open before servicing.

Clearing the buried lines between the pool and the equipment is a separate job, covered by the manuals for your pool and plumbing. This article covers the pump and the filter.

Step 1: Drain and store the pump

Pentair SuperFlo:

  1. Shut off the power at the breaker.
  2. Drain the pump by removing the two drain plugs from the housing, and store the plugs in the pump basket.
  3. Cover the motor to protect it from severe rain, snow and ice, but do not wrap motor with plastic or other airtight materials during winter storage.

Hayward Super Pump:

  1. Turn off the power to the motor.
  2. Remove drain plugs from bottom of strainer body, and remove strainer cover from strainer housing.
  3. To store the pump indoors, Hayward’s next step is to disconnect pump from mounting pad, wiring system (after power has been turned OFF), and piping system, then refit the cover and plugs and keep it in a dry place. Have an electrician handle the wiring if you are not qualified to disconnect it.

Hayward’s storage procedure begins with: drain water level below all inlets to the pool. That step lets the pump come off without water running back in. How low to keep the pool all winter is a different question, answered by your pool and cover instructions.

Whichever pump you have, keep the motor dry, and do NOT cover or wrap pump with plastic film or bags (Hayward), because trapped moisture causes condensation and corrosion. Freeze damage is not covered by Pentair’s warranty, and Hayward says allowing the pump to freeze will void the warranty.

Antifreeze is optional and only for water you cannot drain. If you use it, Hayward says: use ONLY propylene glycol as antifreeze in your pool/spa system. Other antifreezes are toxic and can damage plastic parts.

Step 2: Drain the filter

Sand filter (Hayward ProSeries)

  1. Completely drain the tank by unscrewing the drain cap at the base. Leave cap off during winter.
  2. Press down the valve handle and turn it to set pointer on valve top between any two positions, so the valve drains too. Leave it in that inactive position. Our multiport valve guide explains the normal positions.
  3. Drain and winterize pump according to pump instructions (Step 1).

Cartridge filter (Pentair Clean & Clear Plus)

  1. Open the air relief valve and take the filter apart exactly as the manual’s disassembly steps describe.
  2. Clean the cartridges. Our cartridge cleaning guide covers the method.
  3. Store the cartridges and drain plug in a location where they will be protected from freezing conditions.
  4. Reassemble the empty filter as the manual describes.

DE filter (Hayward Pro-Grid, Pentair FNS Plus)

  • Hayward: in areas where subfreezing temperatures can be expected, the filter should be drained to protect the filter from damage. Take it apart, clean or replace the grids, reassemble, and be sure to leave the drain plug unattached during the winter season to avoid cracking the filter body.
  • Pentair: if prolonged freezing conditions are expected, the filter should be fully drained and filter elements should be removed. Clean them and store the elements and the drain plug where they cannot freeze.

Not sure which type you have? See sand vs. cartridge vs. DE filters.

Step 3: Leave yourself a spring checklist

Put the plugs, caps and cartridges in one labeled bag or bin. In spring, refit every drain plug and cap before the pump runs. Also remove any winter plugs from the pool’s suction fittings: Hayward warns that failure to remove pressure test plugs and/or plugs used in winterization of the pool/spa from the suction outlets can result in an increased risk of suction entrapment. The spring opening checklist covers the full start-up.

The rest of the closing (water, cover, fittings) is in our above-ground winterizing checklist. If you are keeping the pool open through occasional frost, read pool freeze protection instead, and see the pool equipment and circulation guide for how the system fits together.

Sources

Research checked 2026-10-14.

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