Elevated Spa leaks into pool at about 1" per day

[CHorn]

Our 6 person spa loses between 1/2 to 1.5 inches of water per day until it reaches the lowest of the 6 jets.

It appears to lose only when I program the pump to switch twice a day between the pool and the spa. When I do not run the pump at all or when I only run either the spa or the pool modes over several days, it doesn't appear to leak. My pool builder has replaced all of the valves, including check valves, and has twice hired pool leak detectors and no one can say how the water is leaking out back into the pool. They are now telling me to keep the spillway on each day...but that just masks the problem.

The pump system is maybe a couple of feet above the pool level but about the same as the 18 inch high spa.

Any ideas? Thnx.
Carl

 

[ping]

It seems to me that the check valve is still the number one suspect even though it has been changed out. The spa plumbing should not have a leak since it does not leak water while you run the pool in spa mode. Also, if I read this correctly, the pool water level rises when you lose the spa water, is that correct? Post some pics of the pad, it might help us out.

 

[CHorn]

Thnx. I have to reduce the size of my pics as max is 512k. Please stand by.

 

[CHorn]

Here is the pump valve configuration. Pls notice the chk valve barely visible on the left pool return . The small pump on the right is dedicated to the spillway.

 

[ping]

Looking at this layout it seems to me that there is not a check valve between the spa and pool return lines.

If I'm following this right the water comes out of the heater and goes through a check valve, through the SWG, to a 2-way valve, which goes to the pool, (left in the pic), or right to another 2-way valve. I'm not too sure where the water goes from there but it seems to be the spa and something else. If I'm not mistaken the water would slowly drain back to the pool from the spa since it is above the pool and there isn't a check valve between the spa and pool returns.

Hopefully someone else with more experience will help out with their opinion soon.

 

[Qwaxalot]

Unless there's a checkvalve on the little spillway pump, the spa will leak back into the pool.

 

[jblizzle]

I agree, there should be a check valve on the spa return line and possibly on the "little" pump as Qwaxalot mentions.

I think the only purpose of the check valve you currently have on the pool suction line is to prevent the pump basket from draining when you open it ... not really needed at all in my opinion and it is just adding restriction to the water flow.

 

[CHorn]

Thank you all for your input. I've been out. There is a check valve, not in picture to the right on the spillway pressure side of the little pump to the right. Our pool builder's "expert" came out again yesterday while I was out and reprogrammed the system so that the spillway runs 1 hour/day. He still maintains that the spa will always leak down toward the pool level. I still am skeptical ...given that is what check valves are for. You all mentioned a chk valve between the spa and pool return. FYI, there is currently one on the far left for the pool supply, and not on the spa supply which is the other line going to the main pump to the left of the heater. Just to be clear, on the pool/spa return side (right side of pic and schematic) you recommend that we should install a check valve? I have attched a more detailed schematic and noted where I think you are recommending this latest chk valve. (Also, FYI we have a turbo cleaning system which we always use and keep the regular pool returns off.) Thnx very much.

 

[Karmann]

Are you sure your spa drain is closed off 100% when it's draining into the pool.

I have a raised spa and if the spa drain open even just a tiny bit the water level in my spa will drop when my pool equipment shuts off during the night.

Edit: I do keep my spillway going 100% unless I'm heating the spa. I do this so the spa and pool water stay balanced since they are being circulated together as my spa and pool returns are always on and pulled to pump from my skimmers and the main drain in the pool.

 

[CHorn]

Thnx, Martin. All the valves have been replaced or thoroughly checked. The spa appears only to drain when switching between the spa and pool mode. My system is configured so that my spa and pool supply and return lines are either on or off motorized valves era controlled by the programming. Can't run simultaneously, if I understand what you are saying. The only thing I can do at the same time with the pool is run the spa spillway like you do...to share the treated water. Also, American pool leak detectors have sent their young technicians out twice to check for leaks and found none.

 

[Karmann]

good luck, i can't comment on programmable valves since all of mine are manual but according to the pool guy that trained me, the only reason our spa drain would be open is if I'm heating my spa (spa returns fully open, pool returns off, spa drain on, pool drain and skimmers off)

I was schooled about the spa drain when our heat pump was installed because the plumbers for some reason moved our spa drain to be partially open without telling me and i woke up to an empty spa the next morning and freaked out because i thought something was wrong.

It all made sense once i thought about it a little since our spa is raised when the system is not under pressure (pumps off) the water level is going to find the lowest spot available i.e. our pool since the drains are both plumbed into the same system. My spa drain and pool drains don't have check valves like the spa return and spa water feature does so my PB said this is one of the disadvantages of having a raised spa -vs- having a spa that is the same level as the pool and the spa drain open would be a non issue.

In normal use I have the spa return partially open because if it's fully open the spillway can get pretty loud with the rushing water noise.

 

[CHorn]

All makes with your configuration. Thnx.
Will approach my PB about check valve located at spa return.

 

[Qwaxalot]

Does the spa fill back up in pool mode without the spillway pump running? If it does, then the only way it can get there is if the spa return valve is not closing all the way (unless there's a hidden bypass to the spa).

If this is the case then, a check valve where you have indicated will fix the problem

 

[CHorn]

Thnx. No the spa does not fill back up in the pool mode...only (naturally) with the spillway on.

 

[Qwaxalot]

Thnx. No the spa does not fill back up in the pool mode...only (naturally) with the spillway on.

OK, then, according to your diagram & pix, the only way for the spa to drain down is if the check valve on the spillway is funky.

Since it's probably a Jandy valve, you can take the clear lid off and examine the flapper. Look for rips in the flapper, or perhaps a twig or something keeping it from closing.

 

[CHorn]

Thnx very much. Okay. I'll do; but that was done before by the PB. It is a Jandy.
Carl

 

[ping]

I still think there should be a check valve where you drew one in. If the valve that controls the spa and cleaning system fails, the spa would drain in to the pool and a check valve will prevent that from happening. That said I don't think that is your problem right now.

If the spillway valve checks out to be good, then I think it there might be a timing issue with the valves. What is the order that the valves turn when switching from pool to spa mode? The first valve to activate should be the spa return and then spa suction valve should be turned. When switching back to pool mode, the pool suction valve should activate first then the pool return valve should activate. Using this timing the spa should overflow during the switch from pool to spa and spa to pool modes. If you have the opposite timing on the valves your spa would drain to the pool each time it switches.

You say the leaking will go down to the lowest jet, how long does this take? Does it do this only if you are switching back and forth from pool to spa mode?

 

[CHorn]

Thnx, Ping. Both motorized valves are programmed to operate simultaneously and they move slowly. I have always suspected that because they move slowly that water may be leaking back thru one or both of them...but never sure. The pool actually would leak up to about 1.5 inch per day with the spa and pool modes switching back and forth twice a day. Once it gets down toward the jets it really slows down. But I do have a pic from a year or two ago (yes we've been working this issues that long) where it is below all the jets.
I like your idea about staggering the two valves.