I would like to add a "C" / Common wire hookup to my hvac system and get a fancy new thermostat. I've read How can I add a "C" wire to my thermostat? and still have some questions.
First of all, I have an Apollo Hydroheat system. Unusual system I gather. My house has two zones (upstairs and downstairs), both thermostats are connected the same way with four wires:
R - Red, G - Green, Y - Yellow, W - White
Luckily for me, the cable connecting the hvac to the thermostat has unused wires (orange, brown, blue, etc), so I shouldn't need to actually run any new cables.
I found an installation manual for an Apollo Hydronic air handler that has a wiring diagram. The PDF of the Apollo installation manual is here and the wiring diagram is on page 8.
Any thoughts as to whether or not it would be easy to add a live "C" wire? Do I need an external transformer? Can I literally just get a transformer, plug it into a wall outlet, and connect the "C" wire to that?