Another Spa Draining When Pump is Off

[rozannsorensen]

Hi! We bought a house with a pool last summer, and we've been working since then to get the pool functioning properly. The pool has an attached spa that spills into the pool. We usually run it in spillover mode to keep the water circulating in both spa and pool (suction from pool only and return to spa only).

In the last two weeks we've noticed that the spa drains to the level of the seats every time the pump turns off. Having read previous posts, we tried to troubleshoot the problem but have not had success. I know the typical answer is to fix the check valves, however we have zero check valves or automation on this system. So we first replaced the diverter on our jandy valve on the return side, which did nothing. We double checked to make sure we had it aligned correctly. So then we replaced the diverter on the suction side, checked, and double checked alignment, and still the problem persists.

With the pool in spillover mode, if we close the skimmer, cleaner, and main drain when the pump turns off, the water holds in the spa. However, if we leave the skimmer or cleaner open in spillover mode, the spa drains when the pump turns off. (We usually leave the main drain closed all the time.) The pump is a single speed pump, if that information helps.
If it's in pool mode (suction from pool only and return to pool only), the spa holds when the pump turns off. If it's in spa mode (suction from spa only and return to spa only), the water holds in the spa when the pump turns off.

I've learned a lot about pool plumbing, but I'm no expert by any means and this seems to go above my pay grade. Any ideas?

 

[Ahultin]

Is the spa higher than the pool?

 

[rozannsorensen]

Is the spa higher than the pool?

Yes

 

[Ahultin]

I assume the level of the seats corresponds with the pool level. Without a check valve, the spa will always drain to pool level with the pump off and the intake/return valves oriented open to spa at all.

if we close the skimmer, cleaner, and main drain when the pump turns off, the water holds in the spa.

This statement causes some confusion as if there is a makeup line , it would traditionally be on the returns not the intake.

If you fully close intake and return to spa does the spa drain down to pool level? Is there any exposed plumbing near the pool/spa, maybe behind it?

Probably would help if you posted a few more pictures of the plumbing as well as the pool layout and im sure one of the smart people will see it and have an idea

 

[Jimrahbe]

rozann,

Has this ever worked??

I ask because there should be a check valve in the spa return line..

The whole purpose of the check valve is to prevent the spa from draining back into the pool when the pump is off..

It would not surprise me if the check valve is underground... sigh!!

It does not appear that you have a make up line, but more pics would not hurt..

Thanks,

Jim R.

 

[rozannsorensen]

rozann,

Has this ever worked??

I ask because there should be a check valve in the spa return line..

The whole purpose of the check valve is to prevent the spa from draining back into the pool when the pump is off..

It would not surprise me if the check valve is underground... sigh!!

It does not appear that you have a make up line, but more pics would not hurt..

Thanks,

Jim R.

Yes, it has worked up until a few weeks ago. I don’t believe there is a make up line. This is a very, very basic system with no frills. If the check valve is underground it would be in under cement, so I’m hoping that’s not the case.

 

[rozannsorensen]

I assume the level of the seats corresponds with the pool level. Without a check valve, the spa will always drain to pool level with the pump off and the intake/return valves oriented open to spa at all.


This statement causes some confusion as if there is a makeup line , it would traditionally be on the returns not the intake.

If you fully close intake and return to spa does the spa drain down to pool level? Is there any exposed plumbing near the pool/spa, maybe behind it?

Probably would help if you posted a few more pictures of the plumbing as well as the pool layout and im sure one of the smart people will see it and have an idea

I’m not trying to confuse anyone. I’m a novice, so I was just trying different things to isolate the issue. I had to look up what a make up line even is, but I really don’t think we have one. I’ve included more photos on another reply.

If the intake and return are both fully closed to the spa, the spa does NOT drain. There is no exposed plumbing near the spa. All the above ground plumbing is in one area (shown in the photos). The plumbing is in a small, confined area on the side of the house, so it’s hard to get decent photos.

 

[Jimrahbe]

Roz,

Set the Return valve so that the Spa jets pipe is shut off.. Pool pipe is open..

Set the Intake valve to Pool on, and open the Skimmer line and Main drain line..

If the Spa does not drain down, open the Return valve so that the spa pipe and the pool pipes are both open.. If the spa then drains down, then the problem is likely a bad check valve somewhere between the spa jets and the Return valve..

How many jets do you have in the spa??

Thanks,

Jim R.

 

[rozannsorensen]

Roz,

Set the Return valve so that the Spa jets pipe is shut off.. Pool pipe is open..

Set the Intake valve to Pool on, and open the Skimmer line and Main drain line..

If the Spa does not drain down, open the Return valve so that the spa pipe and the pool pipes are both open.. If the spa then drains down, then the problem is likely a bad check valve somewhere between the spa jets and the Return valve..

How many jets do you have in the spa??

Thanks,

Jim R.

It does NOT drain with the intake on pool and return on pool. However it does drain when the return is open to both spa and pool, but it has ALWAYS drained when it’s open to both on the return.

However, what it didn't do before was drain when the return was open to spa only.

I have six spa jets. The water drains 6-8” below the spa jets when the intake is on pool and the return is on spa.

 

[Jimrahbe]

The water drains 6-8” below the spa jets when the intake is on pool and the return is on spa.

Roz,

If the water drains that far below the spa jets, then there has to be an issue with the Spa Drain line... I assume you don't have any other pipes or openings below the spa jets.. Note, the some pools have a fountain or spa overflow pipe in the bottom of the spa.. I do not think you do, but you need to double check.

The spa drain is connected to the Intake valve... When the Intake valve is set to Pool, no water should be able to flow from the Spa side of the Intake valve, but it sounds like it is..

Have you replaced the Intake valve diverter? If you did, are you sure you got the right size? We have seen a couple of cases where the Diverter in an older valve, was slightly longer than the newer ones.

As a test, you could temporarily plug the spa's drain line and see if that stopped the drain down.

Thanks,

Jim R.

 

[Jimrahbe]

but it has ALWAYS drained when it’s open to both on the return.

Roz,

That makes more sense.. Because, without a check valve in the spa return line, that is exactly what will happen..

But, when it drains down due to no check valve, or a bad check valve, it will only drain down to just below the jets.. Not 6 to 8 inches below the jets.

Thanks,

Jim R.

 

[rozannsorensen]

Roz,

That makes more sense.. Because, without a check valve in the spa return line, that is exactly what will happen..

But, when it drains down due to no check valve, or a bad check valve, it will only drain down to just below the jets.. Not 6 to 8 inches below the jets.

Thanks,

Jim R.

I’m thoroughly confused. After messaging Saturday morning, I went to take a picture of the spa when it drained down, but found that it was then only draining to just above the jets (shown in attached picture) rather than several inches below the jets as it had been. The only thing we had changed that morning was replacing the pressure gauge on our sand filter.

Now Monday afternoon, I went out to check, and the spa is holding at the top even with the spa return fully open (shown in second picture). Any idea why the results are changing without doing anything different?

 

[Jimrahbe]

Roz,

Odd indeed...

I guess the gauge could have had an air leak.. Any air leak will cause something to drain down when the pump is off.. Not sure how it would effect just the spa.

Keep an eye on it for a few days and tell us if the drain down problem comes back.

Thanks,

Jim R.

 

[wireform]

Strange that the pressure gauge will make the difference. As @Jimrahbe said lets wait and see.