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Discussion Starter · #1 ·
I am having a power issue with a new 2nd Generation Nest T-stat that I recently installed. I am almost certain that it pertains to the abscence of a C common wire.

I hooked up the 4 wires from my previous Honeywell T-Stat (Yellow, Green, Red and White) to the Nest with no issues. There is a 5th unused blue wire (that I assume could be a common wire.

On the circuit board of my forced air furnace (Armstrong) there are the same corresponding wires (Y, G, R, W and there is a C.

Connected to the C terminal is a white wire that goes to the Nuetral of the Aprilaire Humidistat and the Red wire is connected to the Yellow on the circuit board.

My question: Is the C terminal a common? Can I attach the blue wire to the C at the furnace and to the Common on the nest? will this alleviate the power loss on the Nest?

Thanks
 

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Yes, its a common. You can connect the common of the stat to it.
 

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Discussion Starter · #3 ·
Thanks for reply!

I connected the blue wire (common) to the (C) terminal on furnace that also shares the condenser and I connected it to the common slot on the nest.

I charged the Nest faceplate externally for about an hour. I re attached faceplate and it worked fine for about 45 minutes. The Nest apparently will not charge via the 24v common wire unless it takes 24 hours. This is becoming very aggravating for a $250.00 T-Stat.

I have rebooted several times etc and still it disconnects from the network due to low battery.

Maybe I have a lemon, but very frustrated.
 

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Might call Nest for technical support.
 

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LOL. Sorry, I'm not well versed on the Nest.
 

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Take it back and get a refund or a credit towards a traditional thermostat. I know the Nest has a lot of appeal because of it's learning capabilities but it's not a proven entity. You can get a much better thermostat (almost 2) for what you paid for the Nest. If you fiddle with your thermostat enough to want a Nest you are wasting money anyway. A thermostat with defined settings is much more capable of energy savings than a continuously programmable one. Enough of my rant. You will have to open up your furnace to see which is the common, but I suspect you already have it wired correctly.:whistling2:
 

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Discussion Starter · #8 ·
^^ You are correct, this is too much trouble for a thermostat. I will call their tech support when I get home tomorrow, but I'm sure it's wired correctly.

Any recommendations for a Tstat that can be controlled via smartphone etc?
Honeywell?
 

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Ecobee
 

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I use the 3m-50 filtrete with the cloudbeam.com/our home spaces radio http://store.ourhomespaces.com/ The only app available is for the iPhone, no android or windows phone 8 app available.

As for the problem with the C wire, did you ever check for continuity, to make sure that the wire was not broke somewhere along the line? You can also use a external power source for these thermostats, that would plug in and then connect to the NEST.

Nest may send you out a new thermostat if the one you had did not work after making sure all wiring was properly connected at the furnace, and same at the thermostat. There are also some setup that you have to do on the thermostat, once you get it powered up, for type of furnace, ac/heat-pump, etc..
 

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Good luck with that crap stat. I been on 7 of them so far that customers had to replace them. The display will go away or stat will read 80 deg's for room temp and never change
 

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My wife bought me this exact model for Xmas and sadly I returned it for the nest.

I did spend an unnecessary 90 minutes on the phone with Nest CSR and they think my Tstat needs replacing and they are going to send me another unit.
Well good luck with that.....:thumbsup: I think you may need it.
 
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