Skimmer lid blows off when pump shuts off

harleyd · Postby **harleyd** » Tue 27 May, 2008 15:52

I have a problem that when I shut the pool pump off a major burst of air blows through and out of the skimmer. If I bleed the air out of the filter first it doesn't do it. I have had 3 pool guys here and none of them have an answer.

Guest · Postby **Guest** » Tue 27 May, 2008 20:10

Do you have solar panels in your system? If so, when the system shuts down it could be the water flowing backwards from the roof.

That it doesn't happen when you bleed the air from the filter leads me to think you have a small leak somewhere allowing air into the filter. Most of the air would go right back into the pool as the system runs, but not all. That air would be compressed and when the system is turned off it forces water back through the pump and out the skimmer.

If it's a very old pool it could be the pipe sizing on the return lines being small. When the system gets turned off the water tends to flow backwards through the largest pipes (suction side).

harleyd wrote:I have a problem that when I shut the pool pump off a major burst of air blows through and out of the skimmer. If I bleed the air out of the filter first it doesn't do it. I have had 3 pool guys here and none of them have an answer.

Guest · Postby **Guest** » Wed 28 May, 2008 21:49

install a check valve. problem solved.

Drama pool · Postby **Drama pool** » Sun 08 Apr, 2012 20:41

Did you ever figure out what was causing ths? The SAME thing is happening to me!