Air in Sand Filter

[timrf79]

In my pool the sand filter is the highest element and hence Air accumulates in it.
Not sure if there is a leak on the intake site, but when I turn the pump off, open it.
Fill it with water and then let it run on high RPM, the pump filter (with the window) is full of water.
Once the rpm go down (timer) the water is to the top of the line, over time the water level reduces in the pump filter.
However the pump runs fine.

On the intake side is a 3 way valve, which lets my pull water from the bottom skimmer of the spa or on the other side the pipe goes into a Y which has one 2 way valve each.
One line for the skimmer bottom of pool and one for the 2 top skimmers of the pool.

I tried switching the intakes and closing any of them, but it seems not to make a difference.
Could the 3 way valve be letting air in?

Any other ideas?
I already checked and lubed the pump filter lid and the 2 pump drain plugs.

PS> This is my first pool, bought the house 8 month ago. Any help is appreciated.

 

[Texas Splash]

Air in the system is an indication of a Pool School - Suction Side Air Leaks. Could it be a 3-way valve? - absolutely. So you'll have to inspect each potential area one by one. Just to clarify though ... the title of this thread is "Air in Sand Filter", and then you mention above "the pump filter (with the window)". The small window on the sand filter itself (or multiport valve) is your "sight glass" where you watch for sand & clear water during backwashing and rinse. Then you have the pump "strainer basket" with the clear lid that you look down & into to ensure the pump is always full of water. So I wanted to make sure we were all talking about the same area.

Also, it may help us to update your signature as well. Take a look below at my sig as an example, but the more info about your pool you list the better so we know what you have to work with there. Keep us posted and let us know if you have more questions. Have a good day.

 

[timrf79]

Thank you for the quick response.
I am taking about the pump "Strainer basket".
Should this always be full of water? Because on lower RPM it is only half full.

From your answer it sounds you agree that there is a leak on the suction side.
I think i will use my home warranty and go from there.

 

[Texas Splash]

Knowing more of your equipment specifics may help as well. For example, when you mention low RPM, do you have a variable speed pump? VSPs can often see the water level drop a bit when programmed to run on a low rpm for a significant amount of time. Many VSP owners have their pump programmed to ramp-up for various reasons (cleaning, SWG, etc) which purges that gap of air. If you have a 2-speed pump and run it on low for a while, that can also happen at times. As long as your pump doesn't loose prime that's #1. Use that TFP link above to see if you can find any other indications that may point towards a suction side leak. Also, it wouldn't hurt to check your filter just to ensure there's no restriction effecting efficient water movement through the pump.

 

[timrf79]

I had a pool guy come out and he stated that it is normal to have air in the system and have some bubbles come out of the return into the pool.
The pump is variable speed and low rpm is about 1,200, whereas high RPM is about 2,700.
The pump does not loose prime, it keeps working just fin.

At low RPM it takes about 45 seconds to get the air out the sand filter.