Pump Internal Pressure Build-up

[Dollo]

I have two Pentair Intellipumps on my pool running in tandem,each with it's own filter. The water comes from the pool then is split to the two different pumps and then each pumps respective filter before then going back to the pool. We have had this system for many years. Today when I was checking up on the system I noticed that one pump seemed to be running slow. I checked the status; the first pump was at 3,000 RPM and using a normal amount of power to do so, the second pump (the one in question) also listed 3,000 RPM but only using less than third of the normal power and seemed to be moving a fraction of the water the first pump was moving. I turned them off and opened up the first pump to empty the basket, all was normal. The second pump was difficult to open the basket cover and when it did open it flew off from a large amount of pressure that was built up in the basket area.

What does this mean and how it is remedied?

 

[mas985]

Welcome to the forum!

A pump should never maintain pressure after it is shut off because it should always have a path to release that pressure through the plumbing. Combine that with the lower than normal power and it sounds like something is obstructing the flow in the plumbing.

First thing I would check is to make sure all your valves are set in the correct position.

Next check all the check valves (assuming you have any) to make sure they are operating properly. Can you visually inspect the valve or is it one of those that are completely white?

Lastly, it could be blockage due to debris in the lines.

Is the equipment above or below water level and by how much?

What is the filter pressure for the two paths?

Did you recently vacuum a lot of debris from the bottom?

 

[pooldv]

Welcome to TFP!