Pool pump problems, diagnosed in the cheapest order

The five checks, cheapest first

The reason to do these in order is economic: the first four cost nothing and take minutes, and between them they account for the large majority of what people report as a dead pump. Only after all four should you conclude the unit itself has failed.

1. 1

   1. Water level and the skimmer

   Look at the level before you look at the pump. If the water has dropped below the middle of the skimmer opening, the skimmer is drawing air, and a pump full of air moves nothing and can be damaged. Top it up, then clear the skimmer basket — a basket full of leaves after a storm produces exactly the same symptom. Our after heavy rain guide covers the storm version.
2. 2

   2. The pump basket and the hoses

   Open the pump strainer and clear it. Then check both hoses for kinks, and check every connection for a loose fitting drawing air on the suction side. An air leak upstream of the pump produces bubbles in the return flow and a pump that will not hold prime, and it is frequently just an O-ring that has been left dry or a union that was hand-tightened.
3. 3

   3. The filter media

   This is the most common single answer. A cartridge loaded past the point where rinsing helps quietly strangles the system: the motor sounds normal and the return flow is feeble. Intex guidance for Type A cartridges is roughly every two weeks in heavy use, and if you have not changed one this month, change one now — our cartridge guide is the detail. On a sand filter, check the pressure gauge and backwash.
4. 4

   4. Prime the pump properly

   If the pump is running and moving nothing, it is full of air. Switch it off, open the strainer lid, let water fill the housing from the pool, close it and restart. On above-ground systems that are level with the pool this usually works immediately; if it does not, you have an air leak on the suction side and you are back at check two.
5. 5

   5. Only now, the electrics and the motor

   A pump that is silent and does nothing is an electrical question, and it starts at the GFCI rather than the motor — test and reset it first. A pump that hums loudly, trips the protection repeatedly, or smells hot is telling you something that is not a maintenance job. Our electrical safety guide covers what is and is not a homeowner task here, and repeated tripping is firmly in the second category.

The three faults people misdiagnose most

“The pump is too small.” Occasionally true, usually not. Before buying a bigger pump, work out your actual turnover time — gallons divided by the published system flow rate, not the headline pump flow rate. Intex publishes 475 GPH system flow for the C530 and 750 GPH for the C1000, and a pool inside the pump’s rated size is not undersized, it is clogged. Our pump sizing guide has the arithmetic.

“The water is cloudy so the pump has failed.” Cloudy water with correct chemistry is a filtration problem, and filtration problems are cartridges far more often than motors. Change the media before you condemn the pump — our cloudy water guide starts in the same place.

“It is noisier than it was.” New noise on an above-ground pump is usually cavitation — the pump straining against a restriction upstream and pulling air out of the water. That is checks one to three again, not a bearing.

What a failing pump actually costs you

Two things, and the second is the one people miss. Filtration stops, which is the visible problem. But a pump straining against a blockage is also drawing power to achieve nothing, and pump electricity is the largest running cost of owning a pool — at the EIA US residential average of 18.34 cents per kWh, every 100 W run 8 hours a day for a 120-day season is about $17.61. Our pump electricity guide has the table.

That is also the argument for fixing the cheap thing promptly rather than running a strangled system for a fortnight and then buying chemicals to fix the water it produced.

When it genuinely is the pump

If checks one to four are clean, the housing primes, and the motor still hums without starting, trips protection repeatedly or smells hot, the unit has failed. At that point the decision is replacement rather than repair on almost everything in this category — these are sealed consumer units and parts availability is poor.

Buy to your gallons rather than to the shelf. Our pump roundup covers the options and flags which manufacturers publish wattage and which publish only flow rate, and kit versus separate covers whether to replace the pump alone or reconsider the filtration type entirely while you are at it.