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How to Winterize a Pool Pump

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Quick answer

A pool pump is winterized by preventing freeze-prone water from remaining trapped in the pump and connected plumbing. Shut the equipment down safely, follow the exact pump manual for drain plugs, pot/lid position, unions and storage, and winterize the suction/return lines as a separate plumbing task. Pentair's current winter guidance specifically references removing pump pot and volute drain plugs during severe winter conditions. Do not run a pump dry as a substitute for draining it.

Safety

Disconnect or isolate power according to the pump instructions before opening the pump pot, removing drain plugs or servicing unions. Never work on energized wiring, run a dry pump, or improvise compressed-air line clearing. Use a pool professional when the plumbing layout, blow-out procedure, motor/electrical work or freeze risk is uncertain.

Start with the exact pump model

Locate the pump model and its installation/operation manual before removing anything. Pumps can have different drain-plug locations, pot designs, unions, seals, variable-speed drives and winter storage instructions.

Shut the pump down before water-side service

Turn the system off using the manufacturer procedure and isolate power as required. Photograph the normal valve positions and pump/controller settings before changing the equipment for winter.

Remove trapped water using the pump's drain points

Pentair's winter-storm guidance specifically tells owners to remove pump pot and pump volute drain plugs to give expanding water a path out. A seasonal winterization should use the drain locations and sequence identified by the exact pump manual, not a generic assumption about how many plugs the pump has.

Pool-pump winterization checkpoints
CheckpointWhy it mattersWhat to document
Power isolatedWater-side service should not occur on an energized pumpBreaker/disconnect state and controller mode
Pump pot and wet end drained as the manual specifiesTrapped water can freeze and expandWhich model-specific drain plugs were removed and where they are stored
Lid, O-ring and unions handled per manualSeals can be lost, damaged or installed incorrectly during seasonal serviceSeal condition, orientation and any approved lubricant used
Connected suction/return plumbing winterizedDraining the pump alone does not clear water from the pool linesWho performed the line protection and which plugs/gizmos were installed

Do not confuse pump draining with blowing out pool lines

The pump can be empty while water remains in skimmer, return, cleaner, spa or feature plumbing. Full freeze-climate winterization has to protect those lines through the chosen professional or manufacturer-approved method.

Label and store removed plugs

Put model-specific drain plugs and small parts in a labeled container or attached storage bag where the spring-opening crew will find them. Photograph the empty drain locations so a missing plug is obvious before restart.

Inspect seals while the pump is already out of service

A damaged lid O-ring or drain-plug seal can create air or water leaks when the pump is restarted. Inspect accessible seals without disassembling the motor or drive, and replace only with parts specified for the exact pump model.

Spring startup is part of the winterization record

Before restarting in spring, reinstall the required drain plugs, return valves to operating positions, verify the pump is primed according to its manual and confirm that winterizing plugs have been removed from the circulation path. Do not energize a pump that is visibly cracked or damaged.

What you may need

  • Model-specific replacement pump drain plug only if an existing plug is damaged or missing
  • Pump lid O-ring if damaged
  • Manufacturer-approved O-ring lubricant

Products mentioned in this guide

These are product categories referenced by the guide, not tested or ranked picks. Check the product description, your pool or equipment model, and the seller listing before buying.

  • Pool pump drain plug

    Model-specific drain plug or plug-and-O-ring assembly used on compatible pool pumps. Confirm the exact pump make, model, plug location, and manufacturer part specification before ordering. Winterization procedures commonly require removing existing drain plugs rather than installing a new one.

    Places to check

  • Pump lid O-ring

    Model-specific part — match the exact pump make and model before ordering; O-rings are not interchangeable.

    Places to check

  • Pool pump O-ring lubricant

    Manufacturer-approved lubricant for pump and filter seals.

    Places to check

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About this page

General reference information for pool owners. It is not a substitute for your equipment manuals, product labels, or a qualified local pool professional. Read our editorial standards.