2 Zones / 5 Thermostats

VT

I recently purchased a 3 year old, ranch style house with radiant heating.  From the valves/pipes I see, the house appears to be zoned off in two zones...living room/kitchen and bedrooms/bathrooms.  With that said however, there are 5 thermostats...living room, hallway, guest bed, master bed, master bath.  First, how is this possible if there are only two zones?  Last night I tried turning all of the thermostats off except for the one in the master bedroom, woke up FREEZING!  If they are all turned on, which thermostat "wins"?  Is it possible that there's a waterfall effect in that if the first thermostat on the line is off, none will work?  Any help would be greatly appreciated.  Thanks. 

STEVEusaPA

Anything is possible, however.....

First, can you contact the previous owner and ask them how everything works?

If not, you probably have 5 zones.  Just because you see pipes going in 2 different directions, you may have them branch into different zones, by way of zone valves.  Or you may have valves on your radiant manifolds that are controlled by the thermostats.

Can you take some pics of the controls near your boiler?  Also one a little further back so we can see the piping near the boiler.  And one at each manifold station. Then we can guide you better.