Carrier Heat Pump Wiring Question.

Started by dastx435, March 05, 2023, 11:22:43 PM

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I had an HVAC technician come out and look at my heat pump years ago. He went ahead and said I can make it a conventional system because the gas is cheaper than electricity. I said great he went ahead and rewired the wires going out to the outside unit. Work great for years. Wife went ahead and called someone else to look at it when we had an outage and he disconnected the orange wire going to the outside unit. Now the system is not working. I can get heat but no AC. From what I can tell it all has to do with this orange wire going to the reversing valve. I'm not sure where he hooked it up to and I'm looking for help there. I'm thinking it should be hooked up to the yellow wire so when the AC cycles the reversing switch goes into AC mode. Looking for some guidance here because I'm stuck with a system that doesn't work. Thank you in advance for your help.


Post the model number and/or a picture of the wiring diagram. It sounds like you're on the right track. The only thing I wonder is if there's an issue with the reversing valve not working correctly that someone would disconnect it.
Most heat pumps have the non-energized position as the heat position since heat is a more crucial if the solenoid should fail to work correctly. So it would make sense why you have no cooling if it's not wired up to make the valve switch over.


Come to find out the unit is a Bryant HVAC unit. I have uploaded a couple of pictures that you requested.
Did a search on control board # and Carrier popped up. so thought it was a carrier.

Had an HVAC guy out here and he said he could convert the heat pump to a conventional HVAC system. He said because in Texas natural gas is a lot cheaper than electricity to heat the house. Not sure if that's right or wrong but he rewired the upstairs so that I could only run AC on the outside unit. That is my dilemma now I'm not sure what I should do, to keep the AC and AC unit and the heat a heat unit.

From what I have read the orange loose wire operates the reversing valve in the HVAC outside unit. What I understand from research online is that the default is the heat and you have to cycle the reversing switch solenoid to get the AC working. Just trying to get both systems working.


Heya. Do you think you'd be able to take a pic of the wiring inside your thermostat?


Here is the pis of the thermostat and the outside unit.


And now if you turn on the AC, the unit outside will begin to work, but the temperature that's coming out of the grills is warm?


Yes, feels like heat on.. when the ac is on..



So likely your orange wire is for reversing valve. It was jumped between Y/yellow (compressor) and O (reversing valve).  This way whenever you turned your AC on, it would energize both the compressor and the reversing valve. 

If your compressor is energized without reversing valve being energized, it would be in heating mode and it would heat instead of cool.

Most likely before. Your orange was connected to your O/B at the thermostat and in the thermostat setup it was set as a heat pump.  Right now, your thermostat is likely setup as gas furnace. Which makes thermostat ignore O/B terminal, but energize W to turn on gas furnace heating. 

Now, you need your orange wire be energized whenever Yellow is energized.  When they are both on, you should have cooling.


I think you need to call a different guy to come out and do the reconnect.

Anyone who says gas heat is more efficient than a heat pump shouldn't be working on heat pumps.

Here's the stat manual

- "O" needs to be connected
- blue slider needs to be changed to connect R and Rc
- setup needs to be changed to heat pump