Spa keeps draining into pool

[lthom41pool]

Hi

I'm a new pool owner. So far it has been a journey!!

I have a pool that has a spa connected to it. Once in awhile, the spa drains itself for no reason. Does anyone know why this is happening?
I would appreciate all the help I can get.

Thanks!!

Lisa
IG - 14,000 gallon

 

[jblizzle]

Welcome to TFP!!!

Sounds like a leaking check valve or 3-way valve.

 

[Texas Splash]

The one on top is a check valve. The one below a 3-way. If one is leaking, it causes a pressure equalization issue where water tries to transfer from one part of the system to another.

 

[lthom41pool]

I will take pictures of mine when I get home tonight.. I think it does have something to do with this, just not sure what.
Like I said yesterday.. SPA drained when I turned on filter in POOL Mode, after having SPA on the day before. When I turned filter on, the pump turned on, but no pressure and no circulation in pool. Then, the SPA drained.
Later that day, I switch to SPA mode, then back to POOL mode.. Then, the filter pump worked correctly (I had pressure in filter and water circulating) AND SPA filled itself and it was fine. No clue why, but fixed itself later in day.
I would appreciate all the help I can get to figure out why it is doing this!! Thank you!!

 

[jblizzle]

Hijack was split to HERE.