Pool Pump Noises and What They Mean

Your pool pump runs more hours than almost anything else you own. When it starts making a new sound, it's telling you something, and the sound usually narrows the problem before anyone opens a wrench. Here are the noises that come up most, what each one tends to mean, and how to think about repair versus replacement.

A hum with no moving water

If the pump hums but the motor isn't turning, shut it off at the breaker. A motor that's trying to start and can't will overheat quickly. The usual causes are a failed start capacitor, a jammed impeller (a twig or a bit of debris wedged in the housing) or seized bearings. A capacitor is a small part and a fast fix. A jammed impeller means taking the wet end apart and clearing it. Seized bearings usually point toward a bigger repair. Don't keep switching it on to see what happens. Every try heats the motor windings.

Screeching or grinding

A high squeal or a rough grinding that rises and falls with the motor speed is almost always bearings. They wear out from age, heat, and moisture getting past a failing shaft seal. Early on it's a thin whine. Later it turns into a growl you can hear from the patio. The motor can sometimes be rebuilt with new bearings, but if water has been leaking into the motor for a while, the rest of it is often damaged too. Bearings that scream are worth a prompt call. They only get louder, and eventually they stop the shaft.

Gurgling, rattling and air in the lid

Gurgling and a lid full of bubbles mean the pump is sucking air. The air gets in on the suction side, the part of the plumbing before the pump. Common culprits are a low water level so the skimmer pulls air, a dry or cracked lid o-ring, a loose union, a weeping valve or a cracked fitting. Start with the easy checks: water level, a clean basket, and a lid that seats flat. A fresh o-ring with a bit of pool-safe lubricant fixes more of these than you'd think. A rattle that sounds like gravel is different. That's debris or a broken impeller vane loose inside the housing.

A pump that won't prime

If the pump runs but never pulls water, it hasn't primed. The same air leaks cause it, but so do a clogged skimmer line, a closed valve, a full basket or a worn lid seal. Check the water level and the basket, confirm the valves are open, and make sure the lid is tight with the o-ring in place. Running a pump dry for any length of time damages the shaft seal, so don't let it sit there trying. If it still won't prime after the basics, there's likely a leak in the suction line, and that needs someone with the right tools to find it.

Repair or replace

Plenty of noises have small fixes: an o-ring, a basket, a capacitor, a seal. That's repair territory, and it's worth doing. Replacement starts to make sense when the problem is the pump itself rather than a part on it. Signs that lean toward replacing:

• The housing is cracked or leaks from the body, not just the lid or the seal.
• The motor has failed bearings and has also been taking on water.
• The pump has needed several repairs in a short stretch.
• It's an older unit and the repair would eat up most of what a new pump would take.

An honest diagnosis on the equipment pad should tell you which side of that line you're on. The goal is to fix the part when a fix makes sense and replace the unit only when it doesn't.

Get the noise looked at early

A pump that is allowed to run hot or dry takes the seal, the motor and sometimes the housing with it. A small sound caught on a weekly visit is a small repair. The same sound ignored for a month can become an overhaul. That's one reason a regular equipment check is part of weekly service.

Dallas Pool Service & Repair handles pumps, filters and heaters, from minor fixes to major overhauls, for homes in Allen, Plano and across the surrounding area. If your pump has started making a sound you don't like, call (214) 850-3818 for a free quote.