Please check out my plumbing....!

[Kneedeep47]

All..... I'm new to this site, and its a great source of pool information. I'm also a recent Florida Panhandle resident, with an in-ground pool--my first pool.

My issue: I'm concerned that I may have a "dry priming" issue. The inlet on my variable-speed pump is about 30" higher than the water level in my pool; my pool equipment is located about 35 feet from the pool itself. Each day when the pump starts it goes "low speed" for about 4-5 seconds, and then changes to a higher speed. On start-up, my pump (and the pump strainer) are empty. It takes about 150-180 seconds for the pump to prime (I can see the water flow in the pump strainer) and then the pump reverts back to a lower speed. It continues to run at that lower speed for the remainder of the daily 10-hour cycle.

I'm concerned that the 30" difference in pump location is resulting in the pump intakes (from the skimmer and pool main drains) to run back into the pool, and the resulting "dry prime" period will damage the pump and it's seals.

I don't see any leaks (air or water) in the system. I have no bubbles in the pool outlets that would indicate an air leak in the suction side of the pump while it is operating. I have also tried the "plastic wrap" on most of the plumbing joints in an attempt to find any air leaks in the suction side (and also on the pressure side) of the pump while the pump is off, in an effort to find any air leaks.

I have three intakes into the pump. One (for the spa) is on an actuator valve and in the "off" position--so no water/air is passing through this run. The second intake is from the skimmer, and does NOT have a check valve between it and the pump. The third intake is from the pool's main drain, and it HAS a check valve on it. In addition, there is a horizontally-mounted check valve between the pump outlet and the filter inlet.

When the pump turns off, it takes about 30 seconds for the pump basket to drain below the level of the inlet ports on the strainer. Then (for the next 20-30 minutes) I can watch the pump intake port "burp" air bubbles into the pump basket, as if the drain-back vacuum was pulling air through the pump from the filter side. About the only thing I have not yet checked are the pump seals for air leaks when the pump is off--there is no pump water leak when it is running.

I'm mentally "reengineering" my equipment and wondering if the original install was proper. Without any identified air leaks I'm a loss for why the inlets are draining to the pool. Would an added check valve on the skimmer intake fix this problem? How about relocating the check valve between the pump and filter to just above the pump (and thereby taking advantage of the water column to help seal the check valve)?

Pics of my configuration are attached. ANY help (or even just words of encouragement!) would be appreciated.

 

[Jimrahbe]

K,

Welcome to TFP... A Great resource for all pool owners whether they are a "Panhandler" or not...

Without a doubt you have an air leak somewhere. The fact that your pump is 30" above the pool should not make any difference.

Have you ever taken a straw out of a glass of water with your thumb over the opening? Nothing comes out, because air can't get in. Your air leak is letting your water return to the pool. In a well sealed system your pump basket should stay full for days...

Easy for me to say of course, but harder for you to find. Most of the time the air leak is on the suction side, but it can be on the pressure side also.. Most pressure side leaks would have a stream of water but in some case they can leak air and not water or at least not where you can see it.

I would run the pump and with the basket full, I'd turn off the pump and quickly turn your multi-port valve to off. Does the drain back to the pool continue or not...

I would try this same thing with the valves in front of the pump closed, one at a time, to try and eliminate each individual pipe.

You will just have to keep trying to find the leak until you do.

I guess you could also install a check valve in the line directly into your pump.

I see your pump does not have pump unions... It should be illegal to install a $1,000 pump with out pump unions... Those threaded joints that your pump now has, will usually leak at one time or another...

Thanks for posting,

Jim R.

 

[Kneedeep47]

Jim, thanks for the speedy reply. I checked the multi-port valve yesterday. When I turned it off, I could still hear water draining and I watched the level of the water in the basket drop. Kinda confirms the (air) leak is on the pump/inlet side, to me. I also have some concerns I might have an o-ring air leak in the top-most check valve (between the pump and the filter). I'll do some more detective work today.

Agreed, too, about plumbing in an expensive pump without unions. If (or probably when....) have to service the pump, not having unions will only make my life more difficult.... and it's nice to have some little flex with the union, what with pump vibrations, etc.

 

[Kneedeep47]

Just a quick update...! Yep..... there was a small air leak in the check valve for the Paramount Clear O3 ozone generator(!) at the suction side of the pump. Not big enough to be noticeable when the pump was running, bur during the 12-hour off cycle, it was enough to permit the pump intakes to drain back to the pool level. This apparently had been happening for some time, so as a precaution I also replaced the Intelliflo pump seals, which had suffered through 2-3 minute "dry primes" for about a year (gasp!)....

Everything running fine now. My thanks to the sage advice from Jimrabe and at this forum.... 'Ya guys are winners! Life for the Florida "Panhandler" is back to normal now...............

 

[Jimrahbe]

K,

Thanks for the feedback as this can help others with the same problem..

Glad you were able to get it figured out..

You do know that you could remove that leaky Ozone generator and you would not be able to tell the difference... All "Magic" and no Rabbit...

Thanks,

Jim R.

 

[Kneedeep47]

During my troubleshooting, I used a pair of vicegrips to so prevent the Clear O3 from introducing air into the system. Doing so isolated the ozone generator, but that made no significant difference--the pump intakes and basket still drained back to the pool's water level. The ONLY thing I had not isolated was the ball-check valve of the ozone generator that fits into the Intelliflo pump housing..... And (of course), it was that little valve that was the source of my problems.

Agreed, on the ozone generator. I've had to replace two bulbs and a ballast in the unit over the last 20 months. One thing that is amazing about these "smart appliances"--they seem to automatically know when their initial warranty runs out....and then fail shortly thereafter.

I've elected to remove my Paramount Clear 03 from the system. Too many headaches, for so little added benefit. I'm going to disconnect its 120vac today.....