Need help installing new thermostat in home?
Question:I am trying to wire this thing up, but the wires don't match with the colors on the new thermostat. The lettering on the old thermostat was kind of bunched together so it was hard to tell which wire was connected to which letter, so labeling didn't help. On my new thermostat I have 5 terminals labeled Rh, Rc, W, Y and G. Now, my wires are red (Rh), green (G), blue, and white. I'm not sure what to do with the white and blue. Thanks for any help.
Answers:
Take the red wire and strip it long enough so that you can wrap it around the RH and RC terminals. Take the white wire and connect it to the W terminal. Green goes to the G terminal. Now you can use the blue wire for the Y terminal but you need to go to the furnace and make sure that the blue is not being used for common. I think in this case though they used the blue wire for the Y circuit. You say you already have cooling. So just make sure that the blue wire at the furnace is connected to the Y terminal block at the furnace. Then you can hook up the blue wire to the Y terminal at your T-stat and everything should work.
Make sure that there are two wires connected to the Y terminal in the furnace. One wire comes from your T-stat and the other comes from your outdoor unit. The Y terminal at the furnace basically just acts like a jumper for the two wires to meet. The wire comming from the outdoor unit could be Yellow. Dont worry about the colors not matching up. Just make sure that they are connected to the correct terminals.
Hope I explained this ok for you. Its simple when I do it, but not so simple to explain to someone that doesn't do it for a living.
You have a four wire system and a five wire thermostat. Best off to get teh right kind.
But from what I know: Rh= red heat and Rc= red cool so red = Rh
green is green
white is white
and blue should be Rc
Older systems and base signals on newer ones
Terminal Probable
wire Color Signal Description
C Black 24 Vac Common From one side of the 24Vac transformer (Think of this as 24Vac neutral
R or V Red 24 Vac Power to be switched From other side of the 24Vac transformer (Think of this as 24Vac L1)
Rh or 4 Red 24 Vac Heat call switch power Same as R, but dedicated to the Heat call switch
Rc Red 24 Vac Cooling call switch power Same as R, but dedicated to the cooling call switch
G Green Fan Fan switch on thermostat - is connected to R when Fan /Auto switch is in the fan position
W White Heating call Is connected to R or Rh when themostat calls for heat. (Might be jumpered to Y on a heat pump. On others might be second stage heating
Y Yellow Cooling call Is connected to R or Rc when themostat calls for cooling. Also Cooling or 1st stage heating on a heat pump
Most often connected to G when Fan switch is set to auto
I would tell you to check the manual that came with it.
Here is another source.
http://toad.net/~jsmeenen/wiring.html...
Somebody didn't use thermostat wire!Red is your selector wire(Rheat-Rcooling)if you've already disconnected it,you could have just swapped wires one at a time.You might have the wrong thermostat for your system,24 volt vs. 12 volt,check the back of the packaging.They are NOT interchangable.Didn't say what kind of heater you have.(Forced Air Gas,electric baseboard,forced air electric,oil burner,etc.)
Pull the old wiring out and install all new
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