Replacing Whisperflo with VS in an "oversized" system


Silver Supporter
Apr 28, 2018
Houston TX
I'm the first owner of a fully Pentair-equipped lap pool, 12K gallons. I'm new to pool ownership too, so have been "learning as things break".

Two weeks after the 3 year warranty ended, my heater broke. Pentair authorized the repair, under conditions that would be the last warranty repair. Lots of parts replaced, and back in service for the fall heating season. Great!

Now, one month later, the single speed pump is much louder--it's now a higher-pitched than normal, constant sound, no grinding or rattling, and definitely coming from the motor, no evidence of water leaking.

I'd like to transition to a quieter, more energy efficient VS pump rather than investing in repair of the 3.1 year old pump. It's supposed to be all 2" piping, 2 skimmers, 2 floor drains, and about 90 feet from the pump to middle of the pool. I note that the main drain return entering the valve to the pump is 2.5".

However, this may be part of a cycle of planned "right-sizing" of my builder-selected equipment, as filter and heater are large for the pool and the tethered pressure-side cleaner has some trouble with a lap pool shape (its mounted to wall in the direct middle of the pool, and tends to get trapped at one or the other end).

My questions:
1) Which Pentair VS pump is recommended for my small pool
2) Does the large size of my pool filter raise the minimum flow rate?
3) Does the pressure side booster pump cleaner (Racer LS) raise the minimum flow rate?
3) Does the 400K heater raise the minimum flow rate?
4) Should I add a (for example) Blue-white Flowmeter for 2 in PVC Pipe, horizontal installation, so I have some idea of actual flow rates?
5) Pump is running, but noisy. Aside from the noise--is this super urgent, or might it keep going like this for a long time?

attached is pad pic

Thanks so much for your consideration.


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Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

I would suggest the IntelliFlo VS pump. The larger the VS pump, the slower you can run it and still move a lot of water.

There is almost never a downside to going with bigger than you need, unlike going with something that is smaller than you need.

I see no reason to have a flow meter as they are just not needed in most cases.. You should adjust the pump's speed to make things work in your specific plumbing configuration. There is no need to adjust flow to some "magic" number.. As an example.. the slowest you ever want to run is the speed that turns on your SWCG's flow switch... Just slowly increase the pump speed until the flow light just comes on and then add 100 RPM just to make sure, and you are done.

The same can apply to your heater speed, etc..

The bigger the filter the slower you can run the pump. At 1200 RPM (My SWCG speed) my filter pressure is about 1 or 2 lbs. This is where I run 95% of the time. Because you have a heater, you speed will need to be slight higher, most likely about 1500 or so..


Jim R.


Silver Supporter
Jul 29, 2018
Katy, Texas
Some of your questions are beyond my technical fact, most are. However, I can give you some experience with my system that might help. I have a Whisperflo (2184 watts) running water features, but I just run it 5 minutes a day or when there are visitors. Main pump is a Pentair Intelliflo 3HP VSF 011056. At full speed 3450rpm, it draws 2530 watts. At 1725rpm, 298 watts. At 1650 where I run it 10 hours a day, 260 watts. And at 1300rpm, 111 watts. When running at 1650, it is VERY quiet (can't hear it when the A/C condenser is running). You'll want to check with your heater mfg for minimum flow when the heater is on and your SWG manual for minimum flow for that appliance. Considering all your equipment, the single speed pump is a kind of surprising economy move for only three years ago. Great timing on the warranty, eh?


Silver Supporter
Apr 28, 2018
Houston TX
For completeness: Pentair agreed to a Whisperflo pump repair beyond the 3 year limit. I asked if they would give a credit towards the Intelliflo but this was not offered. Thanks again for the helpful input, I'll consider this as i weigh the option of a upgrade based on sound level and energy cost.