If you have small debris trees around your pool, you may have experienced a problem with clogged pump impellers.
It doesn’t take many pine needles, blossoms, gravel or twigs to clog your pump impeller. Just a small handful will seriously muck things up.
How to tell if your pool pump impeller is clogged
1. The pressure gauge on your pool filter has a normal, clean pressure. Your particular filter may have a clean pressure of anything from 5psi to 30psi. Most systems operate at a pressure close to 10 psi, but it will vary, depending on the resistance from your specific plumbing and equipment. No matter what pressure you normally operate at – when the pressure gauge goes higher, the filter is getting dirtier, increasing resistance.
When the pressure gauge reads Lower than normal, this indicates a suction resistance, some obstruction prior to the filter. This can be a clogged pump basket, closed valves, clogged pipes – or, a clogged pump impeller. When you see your pressure gauge oddly reading much lower than normal, check your valving and pump basket first. If they are clean, you may have a clogged pump impeller.
2. When your pool pump is operating at “Full Head”, the water that you can see through the pump lid will swirl at a particular rate, and may be air-free. When the impeller is clogged, this “swirl” changes; it’s slower and has more air mixed in with the water. This is because the pump is really working hard to pull water through restricted impeller vanes.
3. Your pump will also sound different when the impeller is clogged. You may hear it straining, a bit louder than usual. It may sound like it’s growling or grumbling at you – time to do something!
How to Fix a Clogged Pool Pump Impeller
1. Shut off the pump at the breaker.
2. Remove the clamp band (or 6 nuts) to open up the pump volute, or impeller housing. After removing the clamp or nuts, you may need to use a large flat head screwdriver and some “wiggle” action to slide the motor and seal plate housing back and out of the “wet end” of the pump.
3. Stand the motor up, on it’s back plate, so you can look into the impeller. Use a small screwdriver or steel pick, to reach into the vanes of the impeller and remove the debris. Be gentle, if you are too rough, you can crack the impeller.
4. The impeller will usually have an impeller shroud or cover. If you need to, remove the impeller shroud to gain better access to the vanes. This can be necessary if your impeller is clogged with pea gravel, or small bits of plaster or concrete.
5. Reassemble in the same way, making sure any o-rings or gaskets are properly seated before you tighten up the impeller housing again. Refill the pump with water before starting.
You should now see the pressure gauge back up in the normal range, no longer lower than your normal operating filter pressure. Now that’s DIY pool repair!