Spa draining after shutdown

300winmag

Gold Supporter
Aug 2, 2016
148
Dallas, TX
#1
Question 1:
My typical system setup has been:
"pool mode" (pool main drain & returns only) runs for X hours, then "waterfall mode" (pool main drain, pool returns, and spa return) for X hours, causing the waterfall effect into the pool.
I've been worried about a leak as of late, so to minimize evaporation from the waterfall I adjusted the program to have no fountain mode. It now runs "pool mode" for X hours then switches to "spa mode" (spa drains and returns only) for X hours. To be specific, the pool mode program ended at 3pm, and the spa mode was set to begin at 3pm.

After todays scheduled run times I happened to walk over to the spa and was somewhat shocked to see it's water level 6" low. I checked the equipment pad for water, and it was bone dry. So, I filled the spa up with a hose and activated spa mode. It seemed to hold water just fine for an hour, so I shut the pumps off. Doing so caused the valves to move back to the default "pool mode" and during this time the spa water level dropped about an inch.

Did I lose the initial 6" because my program didn't have any dwell time between pool mode and spa mode? I have since put a 5min period between them but have not run the new program.
Regarding the 1" loss after spa mode shut down, do I have a bad valve seal or maybe the check valve is bad? Regarding the check valve, I only have one and it is on the line that supplies water to the spa during "fountain mode."


Hope this makes sense. Please let me know if you need more detail or pictures.

Thanks guys
 

espejo

LifeTime Supporter
Nov 25, 2014
156
Kingwood Texas
#2
When this has happened to me the usual cause was a faulty backflow check valve. Most manufactures sell a repair kit which requires removing the stainless steel screws and swapping out the internals. Be careful not to torque down the screws too tight. The final turns of the screws should be done by hand.
 

espejo

LifeTime Supporter
Nov 25, 2014
156
Kingwood Texas
#4
The returns are still sending water to spa and the drain is still working when the pump is running. Only when the pump stops will the spa drain back into the pool. This will only happen if the water level in your spa is higher than the the water level in your pool. This is what you need, assuming you have a Pentair check valve.

Check.jpg
 

300winmag

Gold Supporter
Aug 2, 2016
148
Dallas, TX
#5
I think my check valve is a jandy.

Either way, the spa only drops about an inch each time spa mode stops. It does not fully drain down such that the spa and pool equalize water level. I would think a bad check valve would let it equalize?
 

espejo

LifeTime Supporter
Nov 25, 2014
156
Kingwood Texas
#6
I believe the water would equalize if it were a bad check valve. Likely a faulty spa valve which is shutting down just enough so it is draining water more quickly than it is returning. Have you tried shutting off valves and monitoring to see if water level changes. Just thinking of different things I would try to isolate the problem. I doubt it is a leak more likely a valve problem. Try the manual switches and observe to make sure they are switching correctly and fully. Other than these things sorry I can't be of much more help. Perhaps someone else can offer some suggestions.
 
Mar 19, 2017
7
Austin
#7
I had the same issue. The spa level would somtimes fall overnight all the way down, other nights it would be more subtle--never could determine if temperature or other effects played a role in how much the decrease was. As the weeks went on before I fixed it, it became more consistently the full drop. There's also a slow masonry leak into the pool on ours, so we lose an inch or two overnight normally. But, the check valve was an easy fix and did the trick.
 

300winmag

Gold Supporter
Aug 2, 2016
148
Dallas, TX
#8
I inspected both valves that actuate during spa mode, and all of their internals seem fine.

When the pump is off and the valves are in the pool mode position, spa water level does not change. It only loses water during the transition from spa mode to pool mode.
 

300winmag

Gold Supporter
Aug 2, 2016
148
Dallas, TX
#9
Any more ideas?

Pool mode, no issues (pump on or off)
Spa mode, no issues (pump on. Have not tested valves in spa mode w the pump off)
Transition from spa mode to pool mode (pump off), lose ~1" of water from spa. Rough calcs say this equates to 15.5gallons.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,500
Tucson, AZ
#10
Whenever you switch from POOL mode to SPA mode, there is a brief moment when the pump suction is applied to BOTH the spa drains and the pool drains. Because the SPA drains will likely have lower head loss, it is usually the case that more water will be drawn from the SPA and sent to the POOL during this brief transition period. If you cycle POOL and SPA modes enough times, you'll eventually drain the spa. This is why you want to run your SPILLWAY fora short period of time each day as it helps to rebalance the water level in the SPA.

This is often reported happening by people that have FREEZE PROTECT enabled on both the SPA and POOL modes as most automation systems will cycle between POOL and SPA mode every 15mins when FREEZE PROTECT kicks in. Then people wake up in the morning to a drained SPA.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,500
Tucson, AZ
#12
That makes perfect sense, but in my case the system shuts the pump off before the transition. Thus, there is no pump suction, right?
Are you sure about this? Have you physically tested it?

Typically if different programs are set to start and stop at the same time, the pump won't shut off.

Did you test your 5 min off time between them?

Also, even with the pump off, water can still equalize in the suction side. If the suction side valve is transitioning with the pump off, then water can flow from a high point, the spa drains, to a lower point, the pool floor drains.


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300winmag

Gold Supporter
Aug 2, 2016
148
Dallas, TX
#13
I have watched this process many times. My remote app even states "pump will start after delay" if I try to turn spa mode on or off. The pump is definitely off during the transition.

I am not sure about the situation where there is no lag time between programs. I changed that as soon as I thought It might be a problem.

Sounds like i have equalization on the suction side. I will change my program to run the waterfall for 15min after spa mode to fill it back up.

Your comment on freeze protection scares me. Our system only runs pool mode when this happens. I will have to look to see if it can be set to aternate between pool and spa.

Thanks!
 

300winmag

Gold Supporter
Aug 2, 2016
148
Dallas, TX
#14
In the following picture, the far left elbow is the spa supply, and the unlabeled union on the right of the valve is the pool main drain.



Assuming I had room to do so, would putting a check valve in at the location of the arrow prevent the spa water level from dropping after shutdown?
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,500
Tucson, AZ
#16
With the pump off and the valve to the spa suction closed (as is shown), are you getting water staining from the spa to the pool?

If so, then you need to take that actuator off and open up that three way valve because ti should be sealing the suction side off.


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300winmag

Gold Supporter
Aug 2, 2016
148
Dallas, TX
#17
As shown, no water drains from spa to pool.
The spa level drops when spa mode stops (pump off), and the valve actuator is 180 degrees from the position shown in the picture and begins its sweep to the position shown in the picture. The level then remains fixed.

As discussed earlier, it was hypothesized that the water loss from the spa was on the suction side, from the spa drain to the pool drains. Thus, i was curious if a check valve in the noted location would resolve the issue.

Return side has a check valve, as seen here
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,500
Tucson, AZ
#20
Ok. Just checking.

So basically, you run the SPA mode on a schedule each day and, at the end of the schedule, the pump shuts off and the actuator begins to move the valve from SPA open to POOL open.

How much time are we talking about here to move the actuator? 10sec tops?


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