Watch this video if you do not have a C-wire or an extra wire in your bundle. This video demonstrates an alternative option to power your Honeywell Wi-Fi smart thermostat.
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Substitute G-Wire for C-Wire — Install the Honeywell Wi-Fi smart thermostat with this video.
By jumpering G and Y, the blower will be ON whenever the compressor is ON, but will the fan blows the same way when the heater is ON?
Using the G wire as the C wire is a TERRIBLE idea!! I added a Honeywell RTH6580WF to my home recently. I discovered no c wire. Without knowing what all it involved, I found the blue wire tucked into the wire bundle as it had been cut off since not in use. I stripped it and applied it to my thermostat. Still no power. I then went down to my furnace to see the blue wire was not hooked up either it was just wrapped around the same wire bundle going to the thermostat. I stripped it and hooked it to the C terminal on the furnace. Now the C terminal had a white and brown already attached going to the AC. But you can hook more wires to the C. You can hook the 3 right into the terminal or you can bundle them together with a 4 wire called a pigtail then you only have one single wire hooked to the C terminal. User preference. So don't just assume because you found the blue wire in your wall or wire bundle behind your thermostat that its connected to the C terminal in your furnace. You will be best to take the panel off your furnace , find if a C wire is connected and determine the color while making sure it's the wire bundle going to the thermostat.
might as well just pull new wire…
Expands control of the temperature settings in my home>>>t.co/97oEvIn7UL Like it very much.
If you have a wood stove, you will want that G wire to run the fan only
What if the jumper is between RC and RH?
It can work if cooling or heating but when you need at same time system OFF and only Fan running, nothing happen because green in fan relay no receive volts 24 volts
what is you install a jumper between the C and G connector and install the G wire to the C connector….will you still be able to run the fan without the system running????
I have an old Mercury Thermostat with individual wires labeled W-Y-O-B-G-R, this Honeywell RTH9580 WIFI thermostat control board has the W-0/B on the same terminal. How should I wire this?
Is there a way to enable the fan to run separately when not heating/cooling? I need to circulate air when running an HRV.
Tried to install this on my furnace. NO C wire on the old thermostat. Was going to move the green wire from G to C on the furnace NO &^&*% C terminal on the furnace, only a T. Not sure what this thermostat works on. My wife bought this thermostat. I am not sure why she thinks the Russians should be able to control the temperature of our house.
I have simple A/C no Gas heat and only 4 cable no C what I need to do?
THanks for you Tutorial …. I no have C but I don't have heat in my a/c I in florida no need can you please help me ?
Um… I followed these instructions and when it came time to turn on my central AC unit, the fan failed, just as someone stated below. Then, the HVAC people rebuilt it and then the fan didn't shut off. They are now here again and don't understand the wiring of this device. They are putting back an old fashioned thermostat which is really upsetting because I really need the wifi feature of this thermostat.
No the fan does not come on. The AC comes on but NOT the fan.
How about a free exchange for a 4 wire system. Guess nobody at Honeywell has any common logic. They think EVERYONE has a 5 wire system. Mine is ONLY 4!!! This does NOT work on a heat exchanger!!!
I opened my furnace panel and I couldn't find terminals that looked like it did in the video. I seen some on the humidifier but not in the furnace panel.
Is there any reason the G wire, cannot simply be jumpered to the C position? That would seem to supply the needed voltage to both terminals, right? Or would this create a short?
THIS MIGHT HELP SOME OF YOU. To all who DO NOT have a C-Wire and do not have a "Common" on the circuit board:
The "R" Wire is 24 volt power (HOT) coming from the transformer from inside your unit. The "C" wire is 24 volt (NEUTRAL). These two wires are needed for newer thermostat to turn on due to backlighting and other fancy features that require power. My issue was that I did NOT have the C/(Neutral) wire. Because of this, my wifi thermostat did not turn on. So since I had a spare blue cable in the bunch that was not doing anything, I hooked one end to my "C" on the thermostat and the other end to a ground wire that goes back to the main breakers. Once you have that circuit routed, everything should turn on. And I am NOT a license HVAC or Electrician. Do this at your own risk. :P…Hope this helps.
I hooked it all up and now no power on the screen and the furience light is just a steady heartbeat and a humming sound please need help cant find right answer
But now, you cannot make your Fan run independently. Your system has to be on Heat Mode, so it doesn't work if you have a bi energy. (Electrical and Wood stove)
The video failed to tell you to turn off the POWER before proceeding…
I followed these instructions and thought everything was great until I noticed a few days later that my condenser now runs non-stop. What am I missing?
This video helps a lot. However, when I follow my "G" wire to the heater's terminal board, it goes to a terminal marked "CG." Do I still need to move it to the "C" terminal. Also, I do have an extra wire (its blue). Can I just do as instructed and run it from C to C and be done? The CG terminal thing has me a little confused.
For the life of me, I can't understand why this thermostat will not function with only HEATING (Steam / Gas fed).
I know this isn't relevant but the lady's voice in this video sounds a lot like the helpdesk lady from Ratchet & Clank 2
I have a dual system with two thermostats, one for each floor. I followed the instructions but there is a C wire in the heating system but not in either of the old thermostats. Do I still move the G over and attach along with the existing C wire?
As soon as I plugged in the new thermostat, it started blinking on and off with the Honeywell logo. I will have to put in old thermostat until new one can be figured out. I substituted the G-Wire for the C-Wire. Any thoughts from the forum here
At 3:55, it says to run a jumper wire from the Y terminal to the G terminal (after moving the G wire from the G terminal to the C terminal). What if I don't have a Y wire to jump from the Y terminal to the G terminal? My furnace initially only had G, R, and W wires to the respective terminals. My furnace is a York Affinity 9 C series.
very helpful! thank you!
If you move G to C on both ther thermostat and furnace board, can you still connect the air conditioning wire (white) to the C terminal at the furnace board? I'm hesitant to hook it up because I don't want to fry the thermostat…but right now my AC is not hooked up and its starting to get warm!!!
I've been an HVAC tech for 23 years and I had to do this in my parents old house. It will only work on a gas or oil furnace. If you have a heat pump or an electric furnace it won't work.
If you move the G wire from the "G" wire terminal on the air handler, to the "C" wire terminal, and then use the G wire to connect to the thermostat "C" connector, you have done nothing but repurpose the use of the "G" wire itself. It then becomes the "C" wire (even though the insulation may be green)
Doing so will NOT create a fire! RO DU is misunderstanding the instructions!
Removing the "G" wire from the "G" terminal as suggested, only removes functionality to the operation of the fan in manual mode.
Even easier is to just replace the 4 wire bundle with a 5 wire bundle and then use all the wires where they should be used. This will NOT create a fire situation either.
WOW RO DU, IF YOU DO THIS FOR A LIVING YOU SHOULD PROBABLY QUIT BECAUSE YOU DONT KNOW WHAT YOU ARE DOING.
DO NOT SUBSTITUTE A G WIRE FOR C WIRE! THEY ARE 2 DIFFERENT WIRES FOR 2 DIFFERENT PURPOSES! YOU CAN NOT DO THIS! IT can cause a fire or short out your electrical system!