I turned on my spa last night for a New Years Eve dip, but when we got out there we discovered that the water level in the spa was down significantly (over a foot). It wasn't that way earlier in the day. Since then I have checked it a few times and it seems that when the freeze protection mode kicks on, the spa is slowly drained.
I have a shared pump for the pool and spa (Pentair Intellitouch i7+3), and I enabled freeze protection for both the pool and spa circuit so it alternates between them when activated (I also have freeze protection turned on for 2 other feature pumps that are independent of the filter pump). Every time I go out there to check it the valve configuration looks correct, but when I come out an hour later the spa water is down a little more. The valve actuators look like they are working correctly when I change between pool and spa mode myself.
Any ideas where to look?