Low pressure

[Phillbo]

Hello,

The other day I noticed my cleaner (Navigator) was not moving. I also saw that the filter pressure was much lower than normal. I had back washed a couple weeks ago and it dropped to 12psi as is normal, when I checked it after realizing the cleaner was not moving it is at 8psi which is way below normal.

Am I correct in my thinking that this indicates a suction side blockage? I moved the valve that splits the suction between the cleaner and the skimmer so that more suction is going to the cleaner and it will move but the pump noise increases dramatically like it's working much harder to move water.

Any advise on where to look first ?

Also, is the increased noise from the pump caused by cavitation ?

[Poconos]

If the pump quiets down and pressure goes back to normal when you switch to full skimmer then it sounds like you already know what and about where the problem is. Low pressure can also be caused by a gunked up impeller but that would cause low pressure in both paths. The noise probably is cavitation which happens when you have high vacuum areas that cause local boiling. With a blocked suction line the vacuum increases and this could cause cavitation around the impeller or even just pulling air out of solution in the suction line.
Not even thinking about pools in this neck of the woods. Got about 30" of snow a couple weeks ago and under the slush that's left there is a solid block of ice. Bah!
Al

[Phillbo]

Low pressure can also be caused by a gunked up impeller


Ding ding ding .... we have a winner :D

Thanks man, I never thought to check for crap on the impeller. Cleaned off a bunch of twigs and stuff and the system is back to standard operating psi and the cleaner is moving again.


Wishing you an early thaw !!

[Poconos]

Great. I like cheap and simple solutions. Just measured my ice at 11". Got out my backup pump and melted the block off the stairs so I could lower the water level a few inches without crunching them. Getting ready for a bunch of rain in a couple days.
Al