In Floor Heating Issue...

[oldguy00]

Hi all, have a condo with in floor radiant heating. The system doesn't seem to be working properly as the condo won't warm up, floor doesn't feel warm.
The water unit seems to have power.
Of course there are valves all over the place on this, and lots of levers to shut water flow on and off. Also one sort of brass key thing.
I am going to call to have a professional come look at it, but was hoping to learn a bit about it and thought I'd post questions here!

1. There is the air exchanger for the condo a few feet away from the radiant water unit, and there is a drain tube running into air exchanger. When we turned the brass key thing, we heard a rush of water, and all of a sudden there was water pouring out of the air exchanger! Why would they have a drain line going there???
2. So being a genius....I turned off the lever on that drain tube that went to the air exchanger, and turned that brass key on again, again we heard rushing water, and about 10 seconds later we see dirty water coming up through the kitchen drain! So again turned that key thing off again and called it a day.

Does any of this sound familiar? Does it indicate a blockage in the system somewhere???

Thanks!!!!!!