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airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8385
Experience:  Furnace, A/C and heat pump specialist.
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I have a rheem rcba 3765gg17 air handler and looking to hook

Customer Question

I have a rheem rcba 3765gg17 air handler and looking to hook up my new ecobee3 smart thermostat which needs a c wire so I'm trying to find where the extra black wire thats behind the thermostat is in the air handler and then connect to to where it should be for C poer power
JA: Did you double-check the thermostat's settings? And what about the filters?
Customer: the new thermostat settings? yes they explicitly say it needs a C wire and what filter? the A/C filter? I don't think that has anything to do with a C wire
JA: Do you plan on doing the work yourself?
Customer: yes
JA: Anything else we should know to help you best?
Customer: no
Submitted: 11 months ago.
Category: HVAC
Expert:  airheatman replied 11 months ago.

OK first of all the model is for the evaporator coil. Look for a number like RBEA on air handler. Now once inside you will find a brown wire from transformer.You will notice that it is connected to a wire which goes to outdoor unit.That is your C or 24 volt common where you want to connect the C wire from thermostat

Customer: replied 11 months ago.
I see model RBHC-17J06NFD
Expert:  airheatman replied 11 months ago.

Thanks.Let me grab a manual

Customer: replied 11 months ago.
Expert:  airheatman replied 11 months ago.

Locate the transformer. You will see a 24volt hot red coming from transformer going to R at thermostat.Then you will see the 24v common which is brown going to outdoor unit,fan relay and ground. That brown is the 24v common so connect C from thermostat with the browns.

Expert:  airheatman replied 11 months ago.

If you have further questions, please let me know.

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