Wire Question


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Old 06-05-23, 04:06 PM
J
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Wire Question

My thermostat has no C wire. My air handler and compressor outside need the C connection. I have extra wires in my thermostat line. Is there a way to connect one to the thermostat and make it work? Or should I just look for another thermostat? This is just a cool only set up.
thank you,
Joe
 
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Old 06-05-23, 04:37 PM
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Post some pictures of the wiring at the air handler....... How to insert pictures.

If you want to try and find C yourself..... locate the thermostat cable at the air handler. It will be much larger than the condenser cable. The Y- yellow wire in the T'stat cable should go to one of the condenser wires. The other condenser wire will be connected to C.
 
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Old 06-05-23, 04:48 PM
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The common typically originates from the air handler or furnace. You should find it there on the main board.
 
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Old 06-05-23, 05:52 PM
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Yes, I do see the C in the air handler and the C wire in the Condenser, however theres nothing in the thermostat. The diagram shows thet i need to connect the C in the thermostat (which theres no terminal for) to the C in the air handler, then on to the C in the condenser. Seems to me I'd have no control from the thermostat to turn on the condenser. I talked to a rep for white rogers and he said I didn't need a C because the thermostat uses batteries.
Who knows,lol, I'm stumped
I'll ger some pic up on here.
 
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Old 06-05-23, 06:25 PM
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The only reason you need a C wire to the thermostat is if it needs to be powered with 24 volts. If it has or can run on batteries then you do not need to connect the C wire to the thermostat.

Note: It is often required to connect a C wire to a NEST thermostat or other smart thermostat.
 
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Old 06-05-23, 07:26 PM
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Most battery powered thermostats don't require a C connection.
The C connection is to operate the display on some stats as well as the wifi section if a smart stat.
 
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Old 06-06-23, 01:58 AM
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Yeah, I got that, so...my C terminal on the air handler should connect to the condenser outside and i should be good.

thermostat nc air handler ---------C----------condenser
 
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Old 06-06-23, 07:03 PM
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Yes, and you also run the Y wire from the stat to the air handler and from the air handler to the other side of the condenser relay coil.
 
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Old 06-07-23, 05:29 AM
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Here are the photos you requested






 
 

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