Spa Air Blower not working

[jlthla]

So when I got this pool, the air blower for the spa was pretty anemic and VERY loud. it would take several minutes for any air to reach the spa, and then it was only a few bubbles, nothing more.

I bought a new blower, a Polaris 1-480-02 QT Blower 2 HP 240V Bottom Exhaust, installed it and it immediately started working and the water in the spa was roiling, like a big pot of hot water. I used it both in pool mode, where most of the water returns to the pool, and in spa mode, where most of the water returns to the spa. Now, it's not working. The blower is running, I've disconnected the air pipe, and there seems to be a big volume of air coming out of the unit, but none is getting to the spa.

Both the water return pipe to spa, as well as the air pipe go underground, where I assume they meet in some kind of way.

Generally speaking is it possible there is some kind of one way valve there? or is there just generally some kind of "T" connector? I don't mind digging it up to replace the valve but knowing what the usually installation procedure is would be of help.

Also, the blower runs for several minutes, and then stops... there is some kind of thermal cutoff on the unit, so I'm guessing that has a lot to do with it, as well as the fact that the air has no real place to go.