How install new smart thermostat


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Old 11-28-19, 09:31 AM
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How install new smart thermostat

I am trying to replace a older programmable Honeywell thermostat with a EcoBee smart thermostat but am unsure of the wiring. The Honeywell has only the Red, White, Yellow & Green wires connected...there is also a Blue wire coming out of the wall that had electrical tape on it & not used. Is that Blue wire possibly the Common wire need for the new thermostat as C?
 
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Old 11-28-19, 09:37 AM
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It is possible that it is a common wire but you will need to check at the furnace. It is also likely that it is not connected, which is fine as you can then connect it to the common terminal.
 
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Old 11-28-19, 09:44 AM
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The ecobee does come with an adapter to install at the furnace if you have no common wire.
 
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Old 11-28-19, 10:07 AM
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Welcome to the forums.

Remove the blower door to locate the control board.
There should be a terminal strip with a C terminal.

If not....post a picture of the board or the part number on it......How-to-insert-pictures.
 
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Old 11-28-19, 12:35 PM
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Ok I will have to get some help with locating furnace/AC blower door. Not sure on what that looks like.
What would happen if I just hook up the Blue wire as the Common? Would the thermostat work? Or should I just call for help with blower door in attic?
 
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Old 11-28-19, 12:56 PM
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Do you know what your system is ?
Your thermostat needs to be programmed.

Your wiring would suggest a gas furnace with a split A/C system.
What wire colors are on what terminals ?
If it's a furnace..... the door is easily removable.

You could try to connect the blue to C and see if it works.
I would doubt it.
 
 

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