Thermostat / Wire Colors
C? = Brown?
Green = Green
Yellow = Yellow
White = White
RC? = Unused?
R = Red
W2? = Unused?
Y2? = Light Blue?
Gonna go try it real quick. brb
>>945376
Shit there's an orange as well. I see O/B & W on one terminal. W2 is supposed to be black, I think. It's a Trane HVAC btw.
There's really no telling. Find the other end of it and see how he wired it up. I've gotten to the point I never trust anyone's wiring anymore.
It's also old phone color code.
1- Red/Green
2- Yellow/Black
3- Blue/White
4- Orange/Brown
>>945376
Do NOT RELY ON THE COLORS!!!
Often the original installer will have disregarded the color-guide, and just wired the wires how-ever he thought to get it working.
This is why when you buy a thermostat, the instructions even say to mark the wires-connections on the OLD thermostat BEFORE removing.
With your pic, the only way I'd feel comfortable going about that, would be to go to the furnace and VISUALLY inspect what wires are connected to what terminals.
For all you know they wired BLUE to the Common.
Just has a service call this morning, heat-only furnace. The guy had run 4 wire thermostat line, only needing the 2 wires, he connected the thermostat to the furnace on the BLUE and GREEN lines and pushed the RED and WHITE back. Madness.
>>945376
red-hot wire
green-fan
blue-cool
white-heat
Literally just covered this so that's what the wiring would likely be but if you have a second thermostat the other wires may be used so you're on the right track just wrap the others up and stuff em in the wall.
Just test them by holding green/white/blue to the red and see if shit kicks on, it might take a while before the heat/cool kicks on but it's 24 volts and won't fry shit so have no worries there.
my least favorite part of /diy/ is trying to figure out what wires they have coming out of something.
O/B is reversing valve usually color orange. Just look where they land the wires on the circuit board ez
C = Common (Blue/Black)
G = Fan, for your indoor blower fan, not ground! (Green)
Y = Cooling (Yellow)
W = Heating (White)
RC = Power for cooling (Red as well, there should be a tiny Red jumper wire connecting R to RC or RC to RH)
R = Power for thermostat (Red)
W2 = Heating 2nd stage,if your unit a 2 stage heating unit (Brown but it varies by installers)
Y2 = Cooling 2nd stage, if your ac unit has a 2 stage cooling system (Light Blue)
And yes there may be a chance the installer might or might have not followed the standard color guides to hook up your thermostat/ unit!
