Hi -- hoping for some clarity and an easy solution here.
I'm replacing an old HEAT ONLY Honeywell unit with a Nest. Behind the old stat, White wire was connected to W and Blue wire was connected to Rh. There were 3 spare wires not used, Red, Orange, and Green. I currently have the Nest connected using only Blue for Rh and White for W, and while it works, I'm getting power issues so I want to connect a C wire.
If I go to my boiler, the thermostat wires do not connect there directly. Instead there are thicker wires connected to some type of fan relay, and it looks like this:
If I trace where these wires lead, I get to this circular box directly above where my thermostat is. I opened the cover and can see my thermostat wires. It looks like this:
While Orange and Green are clearly not connected to anything, it looks like Red is connected to a wire. I'm wondering if this might be my C wire? Open to any advice here. I'm hesitant to plug red into my C terminal in case it ends up shorting something, so somebody with some knowledge here would be super helpful.
Thanks so much!
