Not sure if I should post this here, or here: https://forums.dansdeals.com/index.php?topic=65068.0
But I'll start here.
I have this very old and very proprietary carrier/bryant thermostat:
(I forgot to take a pic of mine this morning so this is a generic pic I found)
First, anyone know how to get it off the wall? I tried pulling and prying every way imaginable and if I use any more force it will either crack or the screws themselves will come out of the wall. Second, anyone know if I can replace this with a wifi thermostat? From what I'm reading online since this is so proprietary and locked up to carrier I wont be able to use a different thermostat without chaging the control board which I'm obviously not ready to do.
And since I can't get it off the wall I'm not exactly sure which model it is to look for a manual, I found this http://www.graycoolingman.com/uploads/1/0/6/6/10667336/iiuid01-0-1.pdf but I don't know if it's mine and either way, like I said, I tried every possible way to get the face plate off the wall but it wont budge :-(
I recently moved into a house with this same Bryant system and did a bit of research. I'm not very knowledgeable around HVAC systems, but I'll share what I learned.
Despite the thermostat's archaic appearance, mine is actually not that old - it's from circa 2008.
I had the same difficulty attempting to remove it from the wall. We just painted, so I had the painter yank the whole thing, with the screws and anchors, out of the wall in order to fill the holes, anticipating that I would be replacing the thermostat.
Here's a video of how one guy managed to remove it:
https://www.youtube.com/watch?v=deyChaaEh6Y After looking into this system, I will probably just reinstall this thermostat. I haven't yet managed to separate mine from the backing plate in order to reinstall it. Good luck!
I learned that this is an advanced communicating thermostat that pairs directly with the control board in the furnace. It communicates with a whole bunch of complex sensors to monitor all functions of the system and set trouble codes for any faults. There's actual data coming through the wires. It's supposed to be more energy efficient and supposedly "learns" how to control the temp most efficiently in your space. It also allows for more controls, such as variable speeds, and advanced humidity controls.
While it may technically be possible to bypass the smart functions of the system and switch to a "basic" system, it would require extensive rewiring at the control board, and the HVAC techs seem to be yelling at people not to 'downgrade'.
Also, this thermostat runs on just 4 wires because a communicating system doesn't require a separate signal wire for each function. Unless you have additional unused wires running from the thermostat, even if you rewire the control board, you won't have enough wires for standard wifi thermostats, which require at least 5 wires. (it's possible that this issue could be bypassed with one of those Honeywell c-wire adapter kits - I'm not knowledgeable enough for this, but you will still lose humidity controls.)
Maybe someone more knowledgeable here can chime in.
What would probably make the most sense in this situation is to replace the thermostat with a recent model Bryant Evolution/Carrier Infinity wifi thermostat. They're quite costly though, and it means further investing in a 17+ yr old system. (I imagine that the current models of these complex Bryant Evolution/Carrier Infinity systems [compatible with these thermostats if the current system conks] are significantly more expensive than the standard Ruud systems they seem to be installing everywhere.)
