Living with an air leak

[DeltaSmith]

I seem to have a suction side air leak problem, looking for advice on how to deal with it.

This is a 15,000 gallon pool with a single skimmer and a single main drain. There is a suction-side Jandy valve that allows me to select the skimmer, the main drain, or both. The skimmer has a Pentair Vac Mate (vac plate) which supplies suction to both the skimmer and an ancient Hayward Pool Vac Classic. There is a lever in the Vac Mate that allows me to restrict the skimmer flow, which diverts more of the suction toward the Pool Vac.

The Pool Vac seems to need things configured so that it gets the lion’s share of the suction. Otherwise, it gets stuck on the main drain (old style flat drain cover). The problem is that when I configure it that way, I get air bubbles in the pump basket, and I can also hear air bubbles moving through the Jandy valve.

The good news is that when I reduce the vacuum directed at the skimmer, the air bubbles go away. For example, if I flip the lever in the Vac Mate to allow maximum flow through the skimmer (reducing vacuum), almost no air bubbles visible at the pump and no air noise going through the Jandy valve. The problem with that configuration is that the Pool Vac goes slower, doesn’t climb the walls nearly as far, and gets stuck on the main drain.

I considered that the air might be coming from the hose attached to the pool vac. I can’t prove that I’m not (also) getting air through the hose, but I disconnected the hose and plugged the hose side of the vac plate, and I still get air. So I’m thinking it’s probably leaking in underground plumbing somewhere between the skimmer and the Jandy valve. Digging would entail tearing out a concrete deck, so isn’t exactly my first preference.

It might also be leaking at the (25 year old) Jandy valve. I tried spraying it with a garden hose to see if that had any effect on the air noise – it didn’t, but I’m not sure that this is a valid way to test. I haven’t seen any indication of water leaking from the valve when the pump is off.

I’m contemplating that my best option might be to find a way to operate the pool vac without requiring so much vacuum. I’ve thought about replacing the drain cover with an anti-vortex design, but not sure if that would make things better or worse. Hayward has a retrofit kit that is supposed to make the pool vac work better at low flow: http://www.hayward-pool.com/shop/en/pools/v-flex-upgrade-kit-i-vfupkit

Does anyone have experience with this “v-flex upgrade”? Is it worth the investment? Or should I consider completely replacing the old Pool Vac with a newer model?

Thanks in advance.

 

[Wasted0101]

Most vacuum installations recommend turning off the main drain or turning it almost off to avoid it getting stuck. I turned mine almost all the way off and my doesn't get stuck. I figure the vac is already sucking from the bottom of the pool so in essence it is acting as the main drain.

 

[DeltaSmith]

Thanks for the reply. The problem with that solution is that I have to pinch back so much of the flow that my 2 HP pump is circulating less volume than (I imagine) a 1 HP pump would be circulating if the flow wasn't restricted. When this pool was installed in the early 90's, it was designed to use a pop-up cleaning system. If I open the valve to supply return water to the popups, I notice two things: pressure drops from 20 PSI to 10 PSI, and the pump starts making strange sounds and sucking more air. Reducing the head increases the vacuum (I assume), so apparently if I want to maximize the return flow, I have to put up with increasing the amount of air on the suction side, or put up with pump cavitation, or perhaps I'm starting to suck air around the pump seal as well.

My bottom line is that I'd like to restore the flow to something close to what the pool was originally designed for, but in my current situation, that reduces the vacuum to the pool vac to the point where it gets stuck on the main drain.

 

[retfr8flyr]

I have a similar situation, that just started this year. My skimmer line is leaking air and my setup is a one piece fiberglass pool that is in a concrete box, inside a filled area, with a retaining wall around 3/4 of the pool. The cost to replace the line would be astronomical and the system works fine when the Jandy valve is placed on both. My solution was to just leave it on both and get a new VS pump, to reduce the pressure and a robot pool cleaner, as I couldn't vacuum clean anymore. This setup has been working fine all year and unless the leak gets worse next year I can avoid the cost of replacing the line, hopefully indefinitely.