My pool pump does not always prime itself!?

Question

Hey everyone... my inground swimming pool is about 8 years old, and lately I noticed that when I turn the pump on, it no longer primes itself. I have to empty the strainer basket and fill it with water and presto, my pump is working just fine! Any tips? Since the pump works fine after this small inconvenience, is it breaking, or is there an easier solution? A small note, the pump is above the level of water in my pool just in case that matters! Thanks for your help!

Answer 1

It's a little difficult to tell here, but are you saying that if you shut down your pump....leave it...come back to restart ( not taking the lid off), that you find you need to open up the pump lid to put water in to prime because it won't start pumping water within 15 seconds or so if you don't?

There's a small leak somewhere in all likelihood, allowing air into the system when you shut off the pump. It could be anything from a bit of grit on the pump lid O ring to a slight leak on the suction side of the plumbing. Heck, it could be just about anywhere. It may even be a little wear on the shaft seal. Because it's on the suction side of things, you won't see any water leaking. It's suction...not pressure, when you're pump is going. When you turn it off, for a brief moment, the water is under a little pressure as it hammers against a now stopped pump impeller. It may just be the smallest of "squirts", it may not even be big enough to actually let water through ( water is a little "thicker" than air).

Even before you started noticing this, you should always fill that pump up, before re starting it if you had the lid off. Trying to prime without that basket area filled up as much as possible, is putting a little extra wear on the pump's shaft seal. It needs water for lubrication and if it's not getting it or is only getting water that's cavitated, it'll score or burn the seal surfaces.