Where the pump spends the winter

The one rule every pump manual shares

Hayward’s pump manual states it as plainly as it can be put: drain all water from pump and piping when expecting freezing temperatures, and allowing the pump to freeze with water in it will void the warranty.

Water expands when it freezes, and a pump volute is a sealed cavity. The crack that results usually does not show until spring, when the pump is primed and starts leaking from a hairline split in the housing. That is a replacement, not a repair, and it is the single most expensive avoidable item in our bad-close bill.

The frame-pool manufacturers publish the same instruction with numbers attached. Bestway recommends disassembling the filter pump below 50°F and storing it between 50 and 100°F. Intex says to bring pump and filter parts indoors and store them in a safe, dry area, preferably between 32 and 104°F.

The sequence, and the one thing manufacturers disagree about

1. 1

   Lower the water below the inlets

   Hayward's first winterization step is to drain the water level below all inlets to the pool, so nothing can siphon back into the equipment.
2. 2

   Pull the plugs and the strainer cover

   Remove the drain plugs and the strainer cover from the strainer housing. Industry guidance adds the pump volute, the filter tank and the heater if you have one.
3. 3

   Disconnect and drain fully

   Disconnect from the mounting pad, the wiring - with power off - and the pipework, then let it drain completely. Tip it to clear trapped water.
4. 4

   Deal with the filter medium

   Bestway says to remove and dispose of the cartridge rather than storing it. For sand filters, its guidance is to remove the sand and let it dry.
5. 5

   Store it dry and indoors

   A dry area inside, within the published temperature range. Keep the motor dry and covered, but do not wrap it in plastic - trapped condensation corrodes windings.

Antifreeze: what it is for, and what it is not

Pool antifreeze protects pipework that cannot be fully drained. It is not added to the pool water, and it is not a substitute for draining the pump. Hayward’s manual is specific about the type: use only propylene glycol as antifreeze in a pool or spa system, noting that other antifreezes are toxic and may damage plastic components.

On most above-ground pools with flexible hoses, there is very little plumbing to protect — the hoses come off, drain and go indoors. Our antifreeze guide covers the cases where it genuinely applies, which are fewer than the product’s prominence on closing shelves suggests.

Winterizing plugs are the related item that does apply to almost everyone: they seal the skimmer and return so water cannot sit in them and freeze. Our plugs roundup covers the gizzmo, which is designed to be crushed by ice instead of the skimmer.

Storing the chemicals, which is the dangerous part

Pumps crack. Chemicals do worse. CDC guidance on pool chemical safety is to store chemicals in original, manufacturer-labeled containers, store each pool chemical separately in a dedicated location, store incompatible chemicals away from each other, and keep them below 95°F, in low humidity, out of direct sunlight and protected from getting wet.

Two of those matter especially over winter. Protected from getting wet— a damp shed floor and a bag of cal-hypo is a genuinely dangerous combination, and cal-hypo labels warn that exposure to small amounts of water can cause a violent reaction. And separately, away from incompatibles — an unheated garage where shock, acid and algaecide share a shelf is the arrangement most likely to end badly.

Shelf life is the other reason to think about this in autumn rather than April. In The Swim publishes that liquid chlorine can lose up to 50% potency within the first six months and 90% within one year, while trichlor tablets stored sealed at 50 to 70°F retain 98% of available chlorine at 36 months, and properly stored cal-hypo shock has a shelf life of more than five years — but improperly stored bags can dissolve in 12 to 24 months. It also notes that freezing temperatures can ruin algaecide.

What to do with the rest of it

Hoses drain and hang rather than coil on the floor, where the last cupful freezes and splits the end. Ladders and steps come out, get rinsed, and are stored dry — a ballasted drop-in step that has been sitting full of water all season needs draining before it goes anywhere. Test strips and kits are the one thing that genuinely belongs indoors in a cupboard: humidity ruins strips faster than age does.

The solar cover comes off, gets rinsed and dried, and goes away rolled rather than folded. Our take-down guide covers a full pool storage, and our winterizing guide sequences the close for a pool that stays up.

The work takes an afternoon, and it is the cheapest insurance in the whole pool year. Everything on this list is a part you already own, being protected from a failure mode that is entirely predictable and entirely preventable.

Putting it back together in spring

Everything above is easier if autumn leaves a note for spring. Three things are worth doing at the time of storage rather than trying to remember in April.

Bag the plugs and tape the bag to the pump, or put them in a labeled jar with the strainer cover. A missing drain plug in April is a part order and a week without filtration. Photograph the plumbing before you disconnect it, which takes ten seconds and removes all doubt about which hose went where. And note on the filter what medium is in it and when it went in, because sand has a published life of four to five years and nobody remembers the date.

When it goes back together, replace what should be replaced rather than reinstating it. A cartridge that Bestway’s guidance says to dispose of before storage is not improved by a winter in a garage, and our spring opening guide covers the order the rest of it should happen in.