Spa and Filter Pump draining

ofcdduke

Member
Apr 22, 2020
13
Metairie, LA
I have a problem with my spa that doesn't make sense to me. My pool and spa are on the same filter/ heater system. I control the heated water flow to the spa by manually adjusting the valves when the heater is on. When I turn the heat on for the spa, I close the pool intake valves for the pool drains and skimmers. I also close the return to the pool. So When the heater is on, the intake is only from the spa drain and the return is only to the spa. The filter system should only be pulling and returning to the spa. However when I do this, the water in the pool pump has air bubbles and the water level slowly goes done in the pump. The spa water level also begins to lower. I do not see any water leaks, and the pool was recently resurfaced and the deck was redone. There were no leaks in any of the pipes. I am scratching my head trying to figure out where the water is going and why.

I have two theories as to what may be happening and I wanted to hear from yall to see if I might be right. One, concerning the water level in the spa, there may be a leak in a valve that just allows water to pass on a closed valve? maybe if there is a leak in the return valve that is diverting some of the return to the pool, then maybe all the water is not going back in the spa? I think this is unlikely. Two, concerning the water level in the pump, maybe the pump is too powerful for the single 2" drain? I don't see how this would introduce air into the system, or drop the water level, but its all I can think of. The pump does not seem to be working harder when only the spa drain is open. I have attached two pictures to show the plumbing so yall might get a better understanding of what I am describing. Thanks for any help you can offer.pool intake.jpgpool return.jpg
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
43,640
Laughlin, NV
Pool Size
6000
Surface
Fiberglass
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Your valving looks good to me -- but lets give this a bump for some others to take a look.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
22,612
Bedford, TX
O,

I assume this is a spillover spa...

Is the blue ball valve what you use to adjust the amount of spillover?? or???

I suspect that you will find that when they resurfaced your pool that that got a bunch of plaster in the spa drain pipe. You have bubbles in the pump because the pump can't suck enough water through the partially plugged spa drain.

Not sure why the spa water level is going down, but that may be a different issue.

Thanks,

Jim R.
 

ofcdduke

Member
Apr 22, 2020
13
Metairie, LA
I believe the the blue valve was for a slide that is no longer installed. I'm not sure why they left the ball valve in place instead of just capping off the line. The spa is a spillover style spa. The only thing that changes the waterfall rate from the spa is increasing the return to the spa. I was thinking that the pump was being starved for water but never thought the pool contractor would have gotten plaster in the drain. There are check valves on the return lines so I don't think its draining from those. I forgot to mention the spa is elevated above the pool and the spa drains to the level of the pool.
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
22,612
Bedford, TX
O,

If the Spa drains to the level of the pool overnight, then 95% of the time, the check valve in the Spa return line is leaking. Gravity, being gravity, will cause the higher Spa water to drain down into the pool. This drain down normally stops when the Spa water is just below the Spa return jets.

Thanks,

Jim R.
 

ofcdduke

Member
Apr 22, 2020
13
Metairie, LA
He installed a check valve on the pool return and the spa return. If you look at the return picture, the check valves are the unions after the 90 and the T fittings,
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
22,612
Bedford, TX
O,

With the pump off, if the spa drains down to just below the spa jets and stops draining, then the water can only be leaving the spa via the jets. A test for this would be to turn off the spa when full, and then turn the Return valve so that the spa return is shut off.. Let is sit over night and see if the spa drains.

If it drains down below the jets, then your Intake valve where it controls your Spa Drain, could be leaking.

Or... you have a leak in the plumbing itself..

The water has to somewhere.. :mrgreen:

Thanks,

Jim R.
 
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