How to set up my nest thermostat without an existing thermostat. Just 5 wires

[rgaila]

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Original Poster: Leo Barone 

Trying to connect 5 unknown wires to my nest thermostat

[BinaryJay]

Can you post a picture of the wiring?  Usually thermostat wires are colour coded and should be somewhat standardized but the best way for you to confirm which wire does what is to take a photo of the wiring on one side and then go down to your furnace.  Remove the access panel and find where the same colour wires are connected on the furnace control board.  Most of the time the boards will be labeled and you might be able to figure out what is connected to what just looking at it, but if it isn't you'll have to consult the furnace manual which should explain it.   Once you know where the wires are going to the furnace, you can match it up to the required terminals on the thermostat.