HVAC guys. Thermostat assistance needed.

[Rooskibar03]

Just moved into a new place and looking to add a more modern WiFi thermostat, Nest or Honeywell. My understanding is these work on a 4 wire system and most homes have 3.

Well yesterday I pulled the thermostat off the wall and discover it only has two wires, Red and White and the thermostat actually has batteries to power it.

No AC just a forced air gas furnace. Is it even possible to make a newer thermostat work on this system? I'm guessing there will be some wiring involved?

[rbeau30]

http://www.electrical-online.com/the...ing-explained/
This is what I came up with to explain what those two wires control.

Reason why I went to that website is I had another electrical issue that I used that website to get smart on. I'm not an HVAC guy, just a new home owner that likes to tinker.

[hghclsswhitetrsh]

I personally like the Honeywell better.

As far as the wiring is concerned I would pull an 8 wire up there. Do it right the first time just incase you go back to traditional thermostat down the road and would have enough wires for 2 heat, 2 cool, fan, power to thermostat, and a common.

[ruthabagah]

Nest will work fine as long as you do not have a really old, milivolt style, furnace (http://homerepair.about.com/od/heati...urn_coor_2.htm). Just to be on the safe side, you may want to test the voltage coming from the 2 wire you have.

I love my nest. I have had one since they were first released and it's been reliable, easy to use and saved me a bunch in heating / cooling.

[muddywings]

i have the higher end honeywell wifi. it's great! love it. worked great when i just had the heater and it was easy to install. Then I got AC put in and then the AC installer had to use an 'add a wire kit' to add a wire to make it work with the AC or else I'd loose the wifi power. The ad a wire system/kit is pretty cool. From what I recall it's a little wireless transmitter that is hooked to the furnace power supply. A second unit is added to the thermostat. They had to make the hole in the wall a bit bigger and shove the receiver into the wall and let it hang there then put the thermostat plate back on the wall. Never heard of it before but it was pretty cool. Works with no issues and now I have AC and my wifi thermostat.

ETA: Here would be an option- http://www.fast-stat.net/

[ray1970]

Wifi thermostats? Does that mean I can get on the internet and adjust my settings?

[00tec]

Wifi thermostats? Does that mean I can get on the internet and adjust my settings?

Or turn on the ac from the couch. A lot easier to program routines on an ipad too.

[ray1970]

Dang it. Now I need to go look at them.

[00tec]

Dang it. Now I need to go look at them.

Take a look at the Nest. Nifty little thing.

[muddywings]

Wifi thermostats? Does that mean I can get on the internet and adjust my settings?

yup, mine works great if I'm coming home from work early to turn on the heat or the ac.
http://www.homedepot.com/p/Honeywell...7?N=5yc1vZc5kl

My next purchase is a wifi capable sprinkler controller for my lawn and (future) garden next spring. I never found those water sensors reliable so I'm going to one so I can turn on/off the water if it rains.
The Internet of Things is here! also why I invested heavily in the field...SWIR if interested