Nest Learning Thermostat

My furnace is origional from 1938 we have no cooling in the house. I replace the thermostat a few years ago, but can't remember how many wires it had, it was 2 or 3.

A/C is just about a requirement where we live. Too bad heat during the winter is too. The house we are renting needs more weatherproofing as our gas bill for a 1500 sq ft house was over $150 this past month.
 
My furnace is origional from 1938 we have no cooling in the house. I replace the thermostat a few years ago, but can't remember how many wires it had, it was 2 or 3.

The other thing you can do is just run a 24v transformer (like for a sprinkler system) to it. I happen to have a closet behind my thermostat downstairs, so if I didn't have the extra wire, I planned just putting in a transformer in the closet and poking a hole through the Sheetrock to the thermostat.
 
Nope don't have it.
 

Attachments

  • image-1503160219.png
    image-1503160219.png
    282.8 KB · Views: 130
I don't have a C wire. I have G, Y, W, and R and I was able to install my Nest just fine. I guess one of the wires carries the power. I know nothing about HVAC systems so I don't know what the wires do.
 
I don't have a C wire. I have G, Y, W, and R and I was able to install my Nest just fine. I guess one of the wires carries the power. I know nothing about HVAC systems so I don't know what the wires do.

Rh Red -24 Volt Hot for Heating
Rc Red -24 Volt Hot for Cooling
Y1 Yellow -First Stage Cooling
Y2 Blue -Second Stage Cooling
G Green -Indoor Fan
W1 White -First Stage Heat
W2 Black -Second Stage Heat

(not sure for a Heat Pump)
 
I wanted to get one of these when I first heard about them, but I have a heat pump with a gas furnace (very common here). Was told they don't work with dual fuel systems...
 
I wanted to get one of these when I first heard about them, but I have a heat pump with a gas furnace (very common here). Was told they don't work with dual fuel systems...

I have a heat pump with gas. The only option I will loose is "emergency". I have only had to use it 2 times in th 5 years I have lived in my house. I wont miss it. Pop the cover off of your thermostat and compare your connected wires using the compatability section on the Nest site. You can even take a picture of you connections and email it to Nest and they'll let you know if you are compatable.
 
heat pumps typically use the B or O terminal to energize the reversing valve.

most but not all heatpump reversing valves default in heat mode. so when your thermostat calls for heat (with a heat pump) Y or Y1 along with the O terminal are energized.

O terminal is reversing valve in cool mode +24 vac typical.
 
stimpson said:
I have a heat pump with gas. The only option I will loose is "emergency". I have only had to use it 2 times in th 5 years I have lived in my house. I wont miss it. Pop the cover off of your thermostat and compare your connected wires using the compatability section on the Nest site. You can even take a picture of you connections and email it to Nest and they'll let you know if you are compatable.

my new r410 A air source heat pumps produce decent heat down to 18F outdoor ambient.

i am an HVAC tech so i did my own installs. i paid close attention to airflow specs and refrigerant charge.

running goodman 14.5 seer units - one 4 ton and a 2 ton with 95% afue two stage gas furnaces.
 

Users Who Are Viewing This Thread (Total: 0, Members: 0, Guests: 0)

Who Read This Thread (Total Members: 1)

Top