I once connected a Nest smart thermostat to a gas fired boiler by running a new 5 (?) strand wire from the T-stat to the boiler and attaching all the colored wires in the corresponding colored slots. Easy!
Now in a different house I want to do the same thing, but my problem isn't with snaking the wire through the wall, but not knowing where to connect within my Alpine ALP080B boiler. I have a Red and White wire connecting my Honeywell thermostat to my heat-only system. A green wire in that three-strand bundle is not used; it's unattached. The three-strand T-stat wire runs to an electrical junction box in the cellar where the T-stat Red and Green wires are linked by a wire connector with the Red line from the boiler. Another connector links the White wires from the T-stat and Boiler. The wire from the boiler has only a Red and White wire.
Those Red and White wires at the boiler are attached to the slots labeled "Heating T-Stat" in the boiler.
So what do I do? I would run a new 3-strand wire from the Nest thermostat, bypass the junction box, and go directly to the boiler, but I don't know where to put that common wire. There is no place marked "C" or "Common" on the boiler. Surely someone else has these very common Alpine boilers? Nest has a power connector but even that seems like it needs a place to attach to, which the Alpine seems to lack. Any help would be appreciated. Wish I could post photos. Thanks in advance.
