Pressure drop with vacuum


LifeTime Supporter
May 5, 2008
Glenside, PA
22K Gallon in-ground
1 HP WhisperFlo
25' 1.5" Hose
Vacuum Plate

I just installed a new 1 HP 2-speed Pentair WhisperFlo with a 31" Hayward sand filter. When drawing from the skimmer basket or the vacuum inlet on the side of the pool (without vacuum hose/plate) everything looks great with about 11 psi on the filter.

I hook up the vacuum plate to the hose and lower it in the deep end slowly and shaking it every couple feet to release air bubbles and as soon as I insert it in the vacuum inlet the pump basket goes down to about 2/3 full and pressure drops to 3 or 4 psi. I am able to vacuum the pool but not enough suction to get my old Hayward PoolVac up the inlcine from the deep end to the shallow end.

I have 1.5" inlets and 1.5" pipe up to the Jandy diverter. Then 2" pipe to the pump and filter and it gets reduced again before the return pipe goes underground.

Any ideas/suggestions?


TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
SWSuburban Chicago, IL
Can you hold the hose end to the return to force water back thru to the vacume plate, to be sure all the air is out...then keeping the hose end under water hook it up to the vacume inlet...

I dunno.....?


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
Sebring, Florida
Hi, Ken,

You are sucking air into the pump basket. It sounds like it's coming from the vacuum hose. Start tracing your connections from the skimmer to the vacuum head and you'll find one of them is leaking. (or a hole in a section of hose)