skimmer lid blows off

pecker88

Well-known member
Jun 3, 2008
53
weird question here...

noticed that in the past when I would run the pump for only a few mins, then turned off, the skimmer basket lid that allows access from the pool deck would blow off. A geyser a few feet high comes up from skimmer line!

Now, the last 2 days, I've noticed the same thing happens, even after the pump runs all night. Also noticed that the leaf catcher on the vacuum line was blown off this morning.

Why is this happening?
 

JohnT

Admin
Mod Squad
TFP Expert
Apr 4, 2007
9,475
SW Indiana
You probably have an air leak somewhere. Strainer basket lid would be the most common. Air is compressible, so it is compressed in the filter. When the pump shuts off, the air expands and forces water back through the plumbing and you get the geyser.

It could also be low water level or a sticking weir.
 

pecker88

Well-known member
Jun 3, 2008
53
JohnT said:
You probably have an air leak somewhere. Strainer basket lid would be the most common. Air is compressible, so it is compressed in the filter. When the pump shuts off, the air expands and forces water back through the plumbing and you get the geyser.

It could also be low water level or a sticking weir.
air leak as in the pump sucks air? The vacuum hose segments are cracked and suck some air, you can hear it...
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,796
San Dimas, CA (LA County)
Try opening the air bleed on top of the filter. Just crack it a little until it stops hissing and water starts dribbling out. That will eliminate the current air bubble. You need to stop sucking air, though. Any filter element that is in the bubble isn't filtering.
 

4JawChuck

Well-known member
Jun 13, 2010
223
Winnipeg, Manitoba, Canada
On many pools there is an inline check valve on the suction side of the pump, it is there to prevent backflow to the pool and keep the system primed. If this valve has failed you could see reversion to the filter basket causing the filter basket to pop out and throw the lid off. This is caused by water hammer when the pump suddenly stops and the energy of the flowing water to the pump reflects back down the pipe to the skimmer.

To check the backflow preventer valve you need to disassemble the intake side of the pump suction line and try blowing air through it, you shouldn't be able to.
 

pecker88

Well-known member
Jun 3, 2008
53
the plot thickens...

Last night, I cracked open the top of the filter to let out the air bubble, as someone advised above. I cleaned the skimmer basket, and small basket near the pump also.

This morning, went out and although the pump was running, it wasn't pumping any water, I think the pump became 'un-primed'. This has happened in the past, and I was able to fill the small filter near the pump with the garden hose and it took off.

Could this be further evidence that the 'check value' near the pump is mal-functioning...i.e. doesn't stay primed??
 

4JawChuck

Well-known member
Jun 13, 2010
223
Winnipeg, Manitoba, Canada
Could be, was the pump running all night and became "unprimed"?

If so thats another issue, it would be sucking air from somewhere...a common one is the weir sticking and a vortex forms in the skimmer basket which allows air into the suction side of the pump. Lots of places air could come from if the pumps was running and it stopped pumping water...loose connections, lid o-ring leaking (use silicone grease to seal it) etc.

A little trick to prevent the pump from losing prime when the pump is shutoff is to put the multiport into "test" position, this prevents water from backflowing through the filter and back into the pool. Your check valve should do that function however but some pools don't have one installed.
 

Melt In The Sun

TFP Expert
LifeTime Supporter
Oct 29, 2009
3,899
Tucson, AZ
pecker88,
Was the vacuum hose connected last night when it lost prime? If it wasn't, that means you have an air leak somewhere else, and there's no reason to wait for the new hose to start looking for it.
 

pecker88

Well-known member
Jun 3, 2008
53
Melt In The Sun said:
pecker88,
Was the vacuum hose connected last night when it lost prime? If it wasn't, that means you have an air leak somewhere else, and there's no reason to wait for the new hose to start looking for it.
yes, hose was connected when it lost prime.

This seems to happen each time after I clean the small filter near the pump. After unscrewing the transparent top, the water level in the filter lowers and makes a gurgling sound, as I just allowed air into the system. I put the top back on, making sure the o-ring is lubed and in place then turn the pump on....this is where the problem begins.

I have to cross my fingers for the pump to prime and actually start pumping. In the case of last night, it auto. started after we were in bed, and never started to pump; ran all night "dry" until I found it this morning. So, it never recovered after I cleaned the small filter near the pump.
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
11,064
Houston, Texas
Can you give us a little more information about your pool? Is it an above ground or inground? What is the brand and horsepower of your pump, & what type and size pool filter? Next time try opening the air bleed on the filter before opening the pump strainer basket, and leave it open until the pump is turned back on and water squirts out the opening.
 

4JawChuck

Well-known member
Jun 13, 2010
223
Winnipeg, Manitoba, Canada
You should close the return line and place the sand filter into test mode when you clean the basket screen to prevent this happening, try it and see how it works. My pools suction side check valve is shot also and this is what I do to prevent losing prime although my pool pump is only one foot above the pool water level and it will regain prime if I let it run long enough.

Just try it, it works like a charm...you may not even want to fix the check valve if there is one. I'm not ripping my plumbing apart for one silly check valve, I would be removing that unnecessary restriction if I did! :wink:
 
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