Compatibility

[ATC]

 

I could just be grasping at straws because two customer service reps told me the same thing - my system isn’t compatible because my current thermostat utilizes both “B” and “O” wires, indicating we have a heat pump. Shame on me but I don’t really know what a heat pump is. From what Ive read, it’s unlikely because we live in a cold climate (Minnesota) and a new furnace was installed only a couple of months ago. Nothing on the manual of the furnace says the words “Heat Pump” but what I don’t know could fill many rooms. Is this something anyone can offer guidance on? 

[ATC]

Just in case the picture is unclear, wires connected from Left to Right:

B, R, O, W, Y, G

[Houptee]

What is the brand and model number on the outdoor unit, and the indoor unit?

I would go outside and take pic of the decal and google that model number see if it says it is a Heat Pump, same with the indoor unit.

Blue is usually the common wire but some furnace brands call it B instead of C.

[ATC]

Our AC unit is a Carrier 38CKC042---3

our Furnace is a Goodman GMES96

[Houptee]

Just connect the wires to the Nest

Red to RC

Blue to C

Do not use the orange since that AC model is not a heat pump so it is not needed

Y to Y1

W to W1

G to G

[ATC]

I appreciate the help - hooked everything up like you said but it didn’t get power. Just black. May have to just bite the bullet and get professional intervention.

[Houptee]

Did you turn power back on at the furnace?

Do you have a multimeter to test for AC 24 volts between red and blue wires?

[ATC]

I did turn the power back on, tried both Rc and Rh - unfortunately, as soon as this conversation turns into multimeters, volts, etc., I’m in over my head I’m afraid. Again, I appreciate your efforts and I bet your advice will help someone a little more technologically advanced in the future.

[Houptee]

Try with blue disconnected see if it powers on. Red to Rc. Possibly blue is not hooked to common at the furnace. It should power on without a C wire.

[ATC]

Update: had a professional come over to take a look. Ended up being right that I don’t have a heat pump but system was still incompatible. My system has a ‘zone relay’ and apparently smart thermostats won’t work if you have multiple thermostats in your home.

The company google recommended said they’d refund my service appointment which was much appreciated. Not relevant to this discussion but may be helpful to someone else who gets invested in the installation but just aren’t sure.

[Houptee]

You mean you have only one heating cooling system with ductwork, but have 2 or more thermostats that control the zones? It must have a zone duct damper I assume that changes the flow of air thru the ducts to each zone.

[Jhonleanmel]

Hey folks,

We appreciate your help here, @Houptee.
@ATC, I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Thanks,
Mel

[Jhonleanmel]

Hey there,

Checking back in should you still have some questions here. Let us know by replying to this thread.

Best,
Mel

[Jhonleanmel]

Hi everyone,

Just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know.

Thanks,
Mel