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Help Honeywell says i cant be helped C wire issues with wifi thermostat

Help Honeywell says i cant be helped C wire issues with wifi thermostat


  #1  
Old 10-13-13, 05:12 PM
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Exclamation Help Honeywell says i cant be helped C wire issues with wifi thermostat

HI everyone
I just got off the phone with Honeywell. They told me I had to hire a professional Wifi thermostat model RTH6580WF. It's a gas furnace/ac BDP COMPANY unit.
model # is sorta worn but as best as I can tell is 585a036080yac. I dont have any extra unused wires, so my plan was to connect yellow and green together at unit and use the green wire as C wire. I can't figure out where to hook the Wire to at the unit. Here is the picture its a mess. far left in middle of pic is a terminal marked C but it leads to the CAP with purple wire. Does anyone know where the C wire normally hooks up in a older unit? Honeywell told me I couldn't use a external power supply because it was heat and ac unit. not sure of voltage if i was to use an external power supply.
Thanks in advance.

Here is the pic
https://db.tt/MPXSylYJ
 
  #2  
Old 10-13-13, 05:56 PM
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The yellow stat wire feeds one side of the contactor coil. The black wire on the other side of the contactor coil is C.





Stay away from the high voltage C terminal on your capacitor.
 
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Old 10-13-13, 05:59 PM
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I am not familiar with your unit but I can tell you that since you do not have any spare wires you will need to run another wire from the unit to the thermostat. As far as the "C" 24V power source, it is one of the wires that comes from the transformer and goes to one of the 24V terminals on the side of your contactor. In your case, the black wire coming from the transformer and going to the terminal on the side of the contactor is the "common" wire. They make terminals that have two blades so you can run two wires off of one and also "piggyback" terminals for that application. Then it is just a matter of connecting the new wire you ran to the "C" terminal on the thermostat and tapping into the common wire side of the transformer. Make sure you shut the power off and verify it is off with a meter before touching anything inside the unit. Here is two photos of the double tap terminals I like to use.
 
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Last edited by firedawgsatx; 10-13-13 at 06:43 PM.
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Old 10-13-13, 06:11 PM
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You could unplug the G wire from your fan relay and plug it in on the contactor common terminal.
Then get a small piece of wire, 2 spade connectors and a crimping tool to build a jumper wire.
Then place your jumper wire from the Y terminal on the contactor to the G terminal on the fan relay.
Then wire the G wire to C at your new thermostat.


But I would seriously consider pulling wire before attempting this.:NO NO NO:

 

Last edited by Houston204; 10-13-13 at 06:49 PM.
  #5  
Old 10-13-13, 06:55 PM
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Here is a link to some info on your unit that may be useful to you:

http://www.docs.hvacpartners.com/idc...9585dp22-a.pdf
 
 

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