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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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Tim, This past weekend I installed a Rheem Dual fuel 3.5 ton

Customer Question

This past weekend I installed a Rheem Dual fuel 3.5 ton HVAC. I al installed a Honeywell Focuspro 6000. The wires coming from the unit are:
Red, Yellow, Green, Brown, Blue, and White.
I have the thermostat wired as follows:
Thermostat | HVAC
R Red
G Green
Y Yellow
W White
O/B ?
C ?
I also have gone through the programming of the thermostat and was curious if the change over valve is energized on cooling or heating. Also is the fan controlled in heating or cooling due to this unit being a "heat pump? Thanks for your help.
Submitted: 2 years ago.
Category: HVAC
Expert:  Tim H. replied 2 years ago.
Hi, I'm Tim and I'm an HVAC expert here to assist you with your questions. Please provide all information I request as it makes it more difficult to troubleshoot something when I'm not there onsite. Essentially, you become my eyes and ears. Thanks for the opportunity to help. At the end of our dialog, you will have a chance to rate my service, but please wait until we are finished and you're satisfied you have all the information you need.You shouldn't need a C or common on the Focus Pro. Is your unit a heat pump? I think you are saying it is. Down at the furnace, which wire colors do you have on which terminals?
Customer: replied 2 years ago.


Thanks for the response. My unit is a hybrid unit as it is a heat pump but the gas heat kicks in at 35 degrees. Currently I have the wires connected as follows.

Thermostat Terminals HVAC Unit



G Green



Y Yellow

R Red

Rc Red

The A/C is currently working but I want to make sure on the other connections as the unit still has three wires that are not connected. White, Blue and Brown. Below I have listed the colors according to the wire schematic that came with the unit.

Blue Thermostat Connection

Brown C

Red R

Yellow Y

Green G




Expert:  Tim H. replied 2 years ago.
Denny, colors really don't matter here as much as matching terminal to terminal. If there is a red on R terminal at the furnace, for instance, there should be a red on R terminal at the stat, and so forth. On this thermostat you don't really need a C or common hooked up, so the only one left as I can see is the O/B terminal.
Customer: replied 2 years ago.
The wires that are not Hooke up coming from the HVAC are white, blue, and brown.
Expert:  Tim H. replied 2 years ago.
OK, so you'd need to find out where those colors land at your furnace, which terminals. I have to leave for a bit, but will be back later and check for responses.
Customer: replied 2 years ago.

The colors on the wiring in the house match those on the HVAC unit.

Expert:  Tim H. replied 2 years ago.
If this is a heat pump, typically white would go to AUX/E, blue to B, and the other wire is probably a common, not needed.
Customer: replied 2 years ago.
I will try this. Thanks.
I still have one question on the thermostat configuration. Please see the original question.
Expert:  Tim H. replied 2 years ago.
Rheem is the one manufacturer that does NOT energize the reversing valve in cooling. All other manufacturers energize the reversing valve in the cooling mode, because if the valve fails, they want the valve to fail to the heating as heating is more important than cooling.