Hoping I am positing this in the appropriate forum - please see the image below:
Thermostat is a Honeywell TH4110D and furnace is a late 1980's installed Lennox G8D2. What is confusing to me is why the "R" and "Rc" terminals are bridged at the thermostat, and if they should be bridged in this configuration. I ask because I am interested in upgrading to a smart thermostat ("C" is available through an unused wire in the bundle).
Any help is appreciated, thanks.