NOOB: Water shooting up skimmer when shutting down pump.

Jul 13, 2011
17
Hello everyone, noob issue here. I've inherited an above ground 15x30 oval pool that i'm trying to put under my control. I think I understand where I need to take things chemically, but right now I seem to be having a mechanical problem...

I have a Jacuzzi 190L sand filter (no idea on the age of the sand), and a 1HP pump. The pump filter basket has a drip around the big O ring when things aren't running, but its not serious enough to be causing anything anywhere near what i'm seeing.

All of a sudden in the last week whenever I shut down the filter/pump (after running it for say 12+ hours), I seem to get about a 1.5 foot geyser out of the skimmer for a few brief seconds.

I'm not sure if its related or not, but the only thing I can think of doing before this was just trying to use one of those suction brushes that attaches to a pole to clean up the bottom of the pool after we were out of town for a few days.

The return pressure in the pool seems to feel about the same as it did before this started happening (scientifically measured by placing my hand a few inches from the return outlet and feeling how much resistance i have to put up to keep it at that spot).

I noticed that after after cleaning up the pool bottom with that suction brush that day, turning the pump off (for whatever reason i don't remember at the moment, probably backwash/rinse), and then turning it back on caused the return water to appear to be shooting back all that stuff i cleaned off the bottom of the pool (discolored water).

The pressure gauge on the filter seems to be busted, so I ordered a replacement. but not sure what else to try.

I've tried cycling the filter through the various modes of filtering/rinsing/backwashing/draining/whirlpooling in hopes that something would kick over, but alas, i am here seeking guidance :)

i'm leary of running the filter/pump further, worrying that i might be damaging something.

I understand this is a pressure issue, but not sure what its stemmign from. could it be that the sand filter hasn't been changed in forever and a half and just finally got too clogged up after my most recent cleaning?

TIA for any gems you may bestow upon me.
 
Welcome to TFP!

You more than likely have an air leak. As the air gets into the filter, it is compressed by the water pressure. When the pump shuts down, the air expands and pushes water out through the skimmer.

The leak on the pump basket O-ring is almost certainly the cause.
 
Also check your multi-port valve's spider gasket. A bad gasket can cause debris to shoot back into the pool. You may also want to check the stand pipe and the latterals inside the filter if the gasket is good. Look for cracks or loose, dislodged parts. As long as the filter is already opened go ahead and deep clean the sand bed. Carefully insert a water hose down into the sand bed with the water running. Flush the area until the water runs clear. Repeat all over the sand bed. Gently run your fingers through the sand to break up any clumps. Fill filter with water before closing.
 
Thanks guys, I'll get a new O ring ordered. Every time I write down the name of the pump I lose it somewhere before I get around to it... tonight will be different :)

If that doesn't do it I'll tear into the filter itself. Or maybe start on that anyway beforehand. Was leary of opening the filter since I wasn't sure whether plugging up the skimmer hole and the return hole would be sufficient to keep things from creating a flood when I open it.
 
Don't worry about tearing into the filter. Your problem isn't there. It's somewhere on the suction side of the pump. I agree that it's most likely the pump basket lid seal. If it's leaking a bit of water when the pump is off it'll leak a bunch of air into the system when it's running. It's doesn't take a big water leak to be a big air leak.
 
Bama Rambler said:
Don't worry about tearing into the filter. Your problem isn't there. It's somewhere on the suction side of the pump. I agree that it's most likely the pump basket lid seal. If it's leaking a bit of water when the pump is off it'll leak a bunch of air into the system when it's running. It's doesn't take a big water leak to be a big air leak.

I was having the same issue, I opened the pump lid, took, the basket out and then made sure I pushed it all the way down and reclosed the lid. Problem solved. Have you tried making sure the basket is all the way in and the lid is completely closed?
 
The lid is completely closed, but I'm sure the ring has some damage, as it was apparently left in the unit over winter. In any case, won't hurt to plug up the skimmer/return and open/clean it up just to be sure, before a replacement ring arrives.
 
It was the ring(s). I replaced the main cover one and the two on the drain plugs and not a bubble/drip in sight. no pressure build up either.

Now I have to fight to get rid of the green that formed in the pool with it being off for so long :(
 
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