I'm considering getting a Wifi Thermostat if I manage to find one on sale but am unsure if my current system can handle it. My original thermostat wiring was shoddily done, draping across the crawlspace and running along the face of the wall, barely having the length to reach the thermostat. I've replaced the wire with a 5 conductor one and rerouted it for future expand ability. Current, My setup is using two wires which to my understanding isn't enough to power most wifi thermostats and based off my research lacks a common wire? I have a Honeywell RA116A1063 and the wiring is currently connected to the W(T) and B(T) terminals on the stack control. There is an unoccupied R terminal. Is it possible to provide a common with this setup, and what's the unoccupied R terminal provide that the W(T) and B(T) do not? Thanks!

I got a weird situation here without heat in the winter please help: 1. T-stat show "heat on", but I could hear no sound from the furnace or fan. I replaced the t-stat but no help; 2. I could force the furnace(in the attic) to kick-in(I could hear it the noise from the furnace, so I assume it starts, but not sure if it really starts), by turning the switch on the t-stat from "heat" to "off" then "heat" again, but it didn't always start the furnace(again, I just assume it starts from the sound of the furnace). The furnace sound last for about 2~3 minutes then stopped, without triggering the fan to start; 3. I forced the fan to start(turn the t-stat for the fan from "auto" to "on"), when I heard the furnace sound, I could feel the air flow from the vent but I didn't feel it warm, so I thought there was no heat 4. Besides changing the t-stat, I also replaced filters, didn't help; 5. It's weird that once a while the heating does work, about 5~10% of the time of the day, but most of the time including the cold nights, it doesn't work at all, very strange! Now when I try to force the t-stat(manually adjust the target temperature to be above the room temperature), I can only hear the furnace noise for a few minutes, then silent, while the t-stat keeps showing "heat on"; 6. I noticed similar issue in the summer, when I forced turning on the A/C, it didn't always work. I originally thought the t-stat went bad, but problem persists after I replaced it. The heating problem now isn't consistent, but 90%+ of time there is no heat, even I forced high temperature from the t-stat and it shows "heat on". Please advise. Thank you so much!!!