Pump problem...don't know where to start


Well-known member
May 21, 2013
Los Angeles, CA
I'm still having trouble with my pump (an older Pentair Whisperflo single speed). I made a video which should show everything:

Symptoms: low pressure in the filter (under 10 when it used to be 15-20). The filter and skimmer and pump basket have already been cleaned. Very low suction in the skimmer and with the pool vacuum. Water bubbles in the return lines. I've tried adjusting the valve going into the pump to 100% skimmer, 100% side port vacuum, or 50-50. Doesn't make a difference. I regularly release the air valve, and it sometimes lets out some air, but also lets out water at a low pressure (back in the day, water would shoot out vigorously; now it just peters out). The pool itself doesn't seem to be cleaned well -- I see debris both at the bottom and on the surface that aren't getting cleaned.

The filter was cleaned roughly a month ago and we haven't been through an unusually dirty spell. (I usually clean it about 4-5 times a year, and normally if the filter is dirty, the filter pressure would go up, not down. So I'm assuming this is not a problem with the filter.)

No visible leaks that I can see.

I really appreciate anyone who's able to take a look at the video and give me some pointers as to what to do or even search for next.


Gold Supporter
TFP Guide
Jul 21, 2013
Northern NJ
Pool Size
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
I think you need to disassemble the pump and check for a cracked or clogged impeller.

@JamesW thoughts


TFP Expert
Mar 2, 2011
I would open the valve and look inside for debris.

Be careful not to strip the screw threads when reinstalling the screws.

Rotate the screw counterclockwise slowly until you feel the screw drop into the original thread and then go clockwise.

Open the union in front of the pump and check for debris.

Check the lid for air leaks.

Lubricate the oring.

Check the impeller.

Make sure that the basket is installed correctly.


Well-known member
May 21, 2013
Los Angeles, CA
OP Update: I did try searching for leaks by using soapy water (using a technique I found on YouTube) but found no leaks.

Finally, a pool service guy came over today and quickly found the problem. He opened the top of the pump, removed the basket, and fished around with his hand going towards the impeller. He pulled out a small collection of leaves that had clearly been gumming up the works. Took all of thirty seconds and I wish I had known [how] to do that. Closed it up, and the pump was back to full strength immediately. Phew!

I'm posting here in case it helps people in the future!
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