What kills pool pumps, and none of it is running time

Why we will not print a years figure

We checked the manufacturer pages for the pumps we cover and none publishes an expected service life. That is consistent with the rest of this category — the same is true of pools and liners, as our lifespan guide sets out — and it is for the same reason: the owner decides most of it.

These are sealed consumer units running for a few months a year in a benign duty cycle. They are not generally worn out by use. They are killed by four specific events, and all four are avoidable.

One: running dry, which happens in minutes

The single fastest way to destroy one of these. The motor is cooled by the water it moves and the shaft seal is lubricated by it; with no flow, both fail quickly.

It usually happens by accident rather than neglect. The water level drops below the middle of the skimmer opening, the pump starts drawing air, and if nobody notices it runs on. Or a pump loses prime and someone leaves it running while they go to look up what to do — which is exactly why our troubleshooting guide says to switch it off at the socket before working through the checks.

The prevention is the level. Evaporation and splash-out lower it continuously, and a solar cover reduces both. Our skimmer guide covers the operating window, which is narrower than people assume.

Two: winter, which is the other quick death

Water expands when it freezes, and a pump housing is rigid plastic holding a few gallons. There is nowhere for the expansion to go, so it cracks the housing — a failure that happens overnight and is not repairable.

At take-down or closing, drain the pump and filter completely and leave the drain plugs out. Store the unit somewhere that does not freeze rather than beside the pool, and keep the plugs and O-rings together where you will find them. Our storage guide covers the routine, and the unexpected freeze guide covers the version where the cold arrives before you planned to close.

Three: the slow death, which is a filter problem

A cartridge loaded past the point where rinsing helps raises the resistance the pump works against. The motor draws roughly the same power and delivers less, runs hotter, and can begin to cavitate — pulling air out of the water as it strains.

Run a pump like that for a season and you have aged it without any dramatic event. It is also costing you money the whole time, because you are paying for hours to compensate for a part that costs very little: Intex guidance for Type A cartridges is replacement roughly every two weeks in heavy use, with a rinse rather than a scrub in between. Our cartridge guide covers the interval.

The related error is sizing. A pump at the edge of its rated pool size has no margin when the cartridge loads, so it spends more of the season straining. Our pump sizing guide covers buying with headroom.

Four: chemicals where they should not be

Putting chlorine tablets in the skimmer is a common shortcut and a bad one on a pool whose pump switches off overnight. Concentrated dissolved trichlor sits in the skimmer and the pump housing with no flow to dilute it, and it is aggressive to both.

A floating dispenser is the cheapest item in this hub and it removes the problem entirely, while also metering the tablets properly — which prevents the mid-week chlorine trough our tablets versus liquid guide describes.

The habits that add seasons

Check the level whenever you are at the pool. Middle of the skimmer opening. Ten seconds.

Empty both baskets. Skimmer and pump strainer. A basket that fails and lets grit through to the impeller is a mechanical injury rather than a maintenance issue.

Change the cartridge on schedule. Cheap part, expensive consequence.

Shade the pump if you can. Plastic housings embrittle under ultraviolet exposure and lids crack at the clamp points. A simple shade, not an enclosure — it still needs airflow and access, which is also why boxing it into decking is a decision people regret, as our decks guide covers.

Use a timer. Fewer unnecessary hours is less wear as well as less electricity — at the national average rate, each hour a day on a 300 W pump is about $6.60 across a season, and our run-time guide works out how many you actually need.

Where the pump sits in the budget

It is a durable rather than a consumable, which means it belongs in the year-one column and not the annual one — our year two guide sorts every line that way, and the replacement parts guide covers what genuinely recurs. A pump that lasts several seasons is one of the reasons year two of pool ownership is so much cheaper than year one, and all four of the failure modes above are things you decide rather than things that happen to you.