Spa water level rises, but how?

Hey gang,

I have a strange one here, hoping you can help. Customer has pool with separate inground spa, with half of the water below grade and half of the water above grade. There is a flagstone cap without coping on the top wall of the spa, which looks good and is comfortable seating.

Equipment is below water level on hillside. Pool has auto-fill but spa does not. I service the account weekly, and need to drain water out of the spa every week, because the water level rises slowly up to a point where it can seep through the grout under the flagstone cap, then leak down the outside wall and form a puddle on the pool deck.

Sometimes I have found sticks from the nearby bougainvillea causing the weir to jam closed on the spa side of the stopper in the top of the skimmer. Other times even though there is no stick, the weir has somehow flapped to the spa side of the skimmer opening, so water cannot easily get past it into the skimmer.

The pool owner tells me it takes about a day for the spa water level to rise from "mid-waterline tile" to the overflow point.

2 weeks ago, we put a 1" pvc pipe into the ceiling of the skimmer opening space above the weir, preventing the weir from backflapping and getting stuck. Now it takes about 4 days for the water level to increase to the overflow point.

The system is closed, with a pump, filter and heat pump, and a separate booster pump for the jets. The pool water and the spa water do not mix. We have not had measurable rain to blame for the water rising. How could this be happening?

Any ideas? Thanks

Here is a link to a schematic. http://www.idealdistributors.com/et/plans.htm#Plan5

You say the water does not mix BUT ... in case it does, this is probably how it is plumbed. Valve 16 is what you would be looking at and it should be a check valve to prevent water backflowing into the pool when in SPA mode. I use both a shutoff and a check valve if I do one like this.

So, when in POOL mode, a bit of water goes to the spa and to keep it fresh and the excess will usually flow back to the pool through some sort of waterfall. In your case it sounds like maybe a pipe from inside the skimmer and down into the pool. Look for an inlet with very minimal flow right below the spa somewhere, thats probably it, if one exists and the system is plumbed this way.

From your comments I would guess that pipe has gotten some twigs or debris stuck in it and is slowing or stopping the flow.

Another angle to check and possibly the diagram will help clear something up.

Replies

Norman Tyree August 29, 2012 at 12:30am

My thoughts are that if both the pool and the spa end up the same level it is slowly self leveling or even siphoning because of the heat difference.

It is possible that the 2 are some how linked together, is there 1 filter that is shared with heating? maybe auto valves not sealing, otherwise this is a bit of a guess.

Kiwi Norman.
Rick Larson August 28, 2012 at 9:12pm

Here is a link to a schematic. http://www.idealdistributors.com/et/plans.htm#Plan5

You say the water does not mix BUT ... in case it does, this is probably how it is plumbed. Valve 16 is what you would be looking at and it should be a check valve to prevent water backflowing into the pool when in SPA mode. I use both a shutoff and a check valve if I do one like this.

So, when in POOL mode, a bit of water goes to the spa and to keep it fresh and the excess will usually flow back to the pool through some sort of waterfall. In your case it sounds like maybe a pipe from inside the skimmer and down into the pool. Look for an inlet with very minimal flow right below the spa somewhere, thats probably it, if one exists and the system is plumbed this way.

From your comments I would guess that pipe has gotten some twigs or debris stuck in it and is slowing or stopping the flow.

Another angle to check and possibly the diagram will help clear something up.
Scott Roodbergen August 28, 2012 at 5:03pm

I agree with Clinton & Cameron.
You said that there is a pump, filter, & heat pump. So it sounds like a shared filter system for the spa & pool. If that is true then it is very possible that a valve is leaking and letting water slowly add more to the spa.
As Clint mentioned. Shut the filter pump off for a day and see what happens.
The spa water level may actually leak down to the level in the pool if left off long enough.
Cameron McCausland August 28, 2012 at 3:59pm

Id have to agree with clint. sounds like a valve setting issue....

Are there shared return lines between the pool and spa controlled via 3 way valves?

If the spa return line valve is slightly out on an actuator or similar it would cause the spa to fill whilst the pool is in "Pool mode"..

Photos of the equipment set up or schematic showing hydraulic design would be beneficial..
Clint Combs August 21, 2012 at 11:19pm

Possibility 1: The pool and spa water do mix. Pool water is filling the spa. Perhaps there is a leaking valve that should isolate the two. Perhaps there is a dedicated bypass valve is supposed to add water to the pool, but it is adding too much water so that it overwhelms the overflow / equalizer. Such an overflow equalizer might be partially blocked. Try leaving to pool pump off for a day or two to see if the spa level still rises.

Possibility 2: There is an autofill. Perhaps there is a timed autofill that is putting too much water in or perhaps a manual fill valve is leaking so that it doesn't shut off completely.
- Scott Coffman > Clint Combs August 22, 2012 at 5:54pm
  
  Clint,
  
  Thanks for your thoughts. Because the water chemistry tests differently every week, I don't think they mix, but there's a sligtht possibility, and will try leaving the pool pump off for about 36 hours and see.
  
  Also, there is a manual fill valve - I cannot feel any pressure coming from the outlet, but it's about a foot below the spa water surface, so it could be seeping at the valve I suppose. Good thought, and inexpensive to replace just to see.
Jeremy Hine August 21, 2012 at 11:52am

can you quantifiy, "We have not had measurable rain to blame for the water rising.?"

Irrigration pop up heads broadcasting into the the spa/pool? Is that what i see

Whats the likelyhood of the cleaner getting stuck in the corner by the steps and the tail whipping water into the spa?

-Jeremy

Florida Leisure Pool & Spa
- Scott Coffman > Jeremy Hine August 21, 2012 at 3:43pm
  
  Jeremy,
  
  Thanks for your answer, but to quantify: VIrtually no rain. Sprinkler heads all hit the lawn, no overspray. The Polaris sticks on those corner stairs sometimes, but not for long.
  
  None of those potential sources are the "problem".
  
  It only took one night after I was there and drained the spa down to normal water level, several weeks in a row, for spa water level to rise 3 inches and start overflowing again. Then after we put in the piece of pipe to keep the weir flowing the correct direction, it still takes 3 or 4 nights to rise up again. This has been for the last 2 weeks.
  
  I'm thinking of removing the weir altogether to see if that makes a difference.