I resolved a raised spa leak about 4 months ago that was draining overnight with the pump off by replacing the check valve, but the problem appears to have come back. Raised spa loses about 1 - 1.5 inches overnight (sometimes less if not at all). What's odd is that I measured the pool level and it didn't seem to rise, assuming it is related to another bad check valve.
I opened up the spa check valve I replaced last year and it looked good. There is another one for the spa water feature that I haven't opened. I've currently turned off all return to the spa while the pool continues to be filtered so I can see how far down it drains. I had the system completely turned off for 24 hours and when I turned on the pump to the pool, bubbles were coming out of the jets for about 30 seconds (not sure if this is normal).
A couple of questions:
- Would to pool raise in level if an inch of water flowed back from the spa, assuming a 600-700 gallon spa with 18,000 pool?
- Any ideas on what else it could be? Don't know if it's too premature to call out a leak detection company.
Attached are images of the spa indicating the drop in level and the plumbing. This drop occurred over a 18 hour period with the pump off.