Wiring a C (common) wire to a Triangle Tube Prestige Excellence 110?
I think the 24v terminal is the orange one on the bottom right labeled with the ports 7 to 19. you should be able to confirm this by seeing only small (18 or 20 gauge) wires entering into these ports and a red and white wire in location 7 and 8.
I am installing a Nest thermostat and if I need a Common wire, I will add some comments when I figure this out too! I sent triangle tube a request for this information.
Scott