Prime the pump first.

Yes, prime it. That’s almost always the fix when a pool pump hums but doesn’t push water.

Most likely you’ve got an air lock — air trapped in the pump housing blocking the impeller from pulling water. The solution is simple: turn off the pump, unscrew the clear lid on top of the strainer basket, fill the basket with a hose until it’s full of water, put the lid back on tight, and turn it back on. Water should start flowing in seconds.

If that doesn’t work, check the strainer basket for debris, make sure the weir door in the skimmer isn’t stuck closed, and look for a closed valve on the suction side. Also — is the water level in the pool high enough? If the skimmer is sucking air, the pump will lose prime.

Don’t let it run dry for more than a minute or two. The pump seal will overheat and fail, and that’s way more expensive than fixing a $50 lid O-ring.

Future You doesn’t want to replace a pump seal just because you skipped the easy check.