Aside from the motor, the pool pump impeller is the only moving part of your pool pump, which makes it very susceptible to damage. The pool pump impeller spins at high speeds, creating the vacuum that provides the force needed to draw in the water from the pool and pushes it out through your pool filters.

Dangers of a clogged or damaged impeller

Low water pressure or decreased water flow will be the least of your problems if your impeller is clogged or damaged. The low water flow will prevent the pump from cooling down as it operates and there’s a large chance that your shaft seals will melt and fail causing what’s known in the pool biz as a “blown seal” which will lead to a leaky motor, and eventually a whole pump failure.

Symptoms of Impeller Clogging or Damage

Here are some signs you need to look out for when you suspect that your pool pump impeller is clogged or damaged.

• Pool pump surge or pulsing - A clogged or damaged impeller can cause inconsistent suction causing your pool pump to surge.
• Decreased water flow - This can be checked visually via your pool pump lid. Low water flow or if the basket doesn’t fill up with water then it’s very likely that there’s something wrong with your impeller.
• Low pressure - If your cartridge filter or sand filter pressure gauge reads very low pressure even after cleaning or backwashing then there is a possibility that the impeller is clogged or damaged. 
• Loud cavitation noises - If your pump is making noises that are low pitched and extra loud, like an animal growling then there’s a large possibility that your pool pump impeller needs to be looked at. 

Troubleshooting your pool pump impeller

Before buying a new impeller (they can be quite pricey) try and troubleshoot it first. Turn off your pump, clear your pump basket, and with a small wire or if your have slender fingers, try and dislodge any leaves or debris that may have been trapped in the impeller. 

If that doesn’t work, then you may have to open up your pool pump. Check out this helpful article on the parts of a pool pump to help guide you through the process. 

To make the process much easier, detach your pump (this is where pool pump unions shine!) from the pipes and move it so you’ll have a more comfortable position opening up your pump. Remove the volute by removing the seal plate bolts or the clamp band holding the housing in place. Pull back the motor (you may want to let the motor cool down for a few minutes) to expose the diffuser or impeller shroud. Remove the shroud and you should see the impeller exposed. Thoroughly clean the impeller with a wire and reassemble the pump and everything should be back to normal. 

Replacing your pool pump impeller

Follow the steps above to exposure your impeller, remove it then slot in the new impeller and you should be good to go.

Important note: If you’re lucky and you caught the impeller damage early then that should be just that. When you encounter impeller damage, also check your mechanical seals, and your seal plate O-ring since these are usually damaged whenever the pool pump overheats due to a damaged impeller.