Heating, Air Conditioning, Fridge, HVAC/AC question


I recently purchased the HoneyWell WIFI Thermostat but found out the the C wire is not connected in the Rheem  AC (RCBA 365A517 as a result no power is going to the Thermostat

How do I connect this wire in the AC unit

I can see the wire at the AC end. Its cut short almost hidden in the brown cable that comes form the current thermostat


The C wire is common / neutral.  The C wire connects to a bare metal surface in the air handler, or to the terminal on the transformer that is also going to bare metal.  The other end then connects to C on the back of the new t-stat.  Hopefully you have enough wire to make it work, otherwise you might need a small piece to make it reach.


Heating, Air Conditioning, Fridge, HVAC

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Craig HVAC Expert


I have been in the HVAC field for the past 18 years. I can help with most HVAC questions. I work on commerical buildings for the most part, and have yet to find anything I could not troubleshoot and repair, when repairable. I work on small 1 ton units to a 2500 ton chiller. Troubleshoot air flow, elect, and control problems. I attend regular classes to keep up with the latest and greatest.


I work on commerical sites, hospitals, gov't buildings. I can troubleshoot just about anything in the HVAC business.

5 years trade school, VFD training classes, Liebert factory training, some York and Trane factory training.

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