DE Filter creates geiser thru skimmer when turned off q's

[PatL34]

From what I have been reading from all these threads, I keep thinking that the problem seems to be with the multiport valve.

If it is the type that you pull up and push down for backwashing, one of the seals may be worn out.

With the Hayward Multiport type, the seal between the casing and the top may be leaking, allowing air to be drawn in.

Just my thoughts.

(Poconos. I still like to see a check valve downstream of the pump. It protects the pump seal and the motor. Standard engineering practice.)

Pat

[rio002]

I checked all hoses, no slits or holes to be found and made sure all clamps were in the right places and tight. I did find one pvc connection that goes from the pump to the filter/multivalve control that looks tight, but actually has some play in the threads, tightened it up and will check tomorrow morning. I did notice my psi was sitting between 15 and 20 (when it's this low it doesn't do the geiser thing, provided I open the air valve long enough) today so perhaps I have had several small air leaks that are slowly being taken care of by retightening all the clamps yesterday and the pvc connection this evening? I'll let you know in a.m.

[Poconos]

Pat, the only objection I have to check valves is the additional restriction they present to the system just because of their structure and turbulence they generate. Of course you could go grossly oversize on the valve but then the cost goes way up and I'm a cheap guy. But, when you consider the investment in equipment and the pool, one shouldn't care about another $20 or so. Also, your comment about the multi-port valve, this is on the pressure side of the pump. Air wouldn't come in, water would be blown out. Air leaks have to be on the suction side.
Al

[rio002]

Well three knuckles a bleedin' later, took off the hoses and pvc fittings that lead from the pump and return jet to the side of the multiport valve. The one from the pump did have a small leak that I hadn't seen because it was dripping into a bucket containing extra de--which never looked wet until you touched it, apparently whoever originally did this--had issues about plumbers tape, all of it was ran backwards (so when the pieces were threaded back on all the tape was bunched up and not in most of the threads) fixed that and the leak. Let it run for 4 hours. Now it's to the point where if I open the air valve all the way for 15 seconds, (timed it) the air is fully out, psi reads 10-15 and I can shut it off without even a belch through the skimmer or anywhere else. Now if this sounds like normal procedure for one of these, then you guys were right about it sucking air through very small places and we have it fixed--if it doesn't sound right then please let me know, like I said this is my first de filter, so I am depending on the experience here--which let me tell you has been excellent so far.

[rio002]

AAAHAAAA! I think lol.........ok I shut it off tonight the same way I mentioned before (after letting the air valve open til it ran just water) after I shut it off I closed the air valve and for several seconds (about 15 or so) I could still hear and feel air coming out of the air valve that was closed. So technically couldn't this be where it's sucking the air in from?
It bugged me all day that while I can get the geiser to stop by using the air valve prior to shutting it off, doesn't it reason that I am merely treating the symptom?
I tried tightening the air valve (just by hand) to see if I could get it to stop, but it just kept pushing air out, not a huge amount, but in my mind I would think that over several hours of running that it could suck in enough air to cause my geiser problem. Does this sound on track?