Help wiring 3rd gen

[Rhombus78]

I just need help wiring my nest 3rd gen learning thermostat. My current Carrier unit has the following wires 

2 red wires to R

Green to G

Yellow to Y/Y2 

2 white wires to C

Blue to B

 

 

 

[Rhombus78]

Any feedback would be greatly appreciated 

[Rhombus78]

Anyone??

[Ryan_G]

Hi Rhombus78,

Thanks for reaching out here in the Google Nest Community and for sharing these photos with us.

Based on your current wiring configurations, your HVAC system is compatible with the Nest Thermostat. The only difference is the 2 red wires that are connected to R from your old thermostat. You'll be using those wires and connecting it to the Rh and Rc terminal on the Nest Thermostat. The blue wire could be on a C wire terminal on the Nest Thermostat.

Let us know how it goes by replying to this thread.

Best regards,

Ryan

[Rhombus78]

Thanks for your reply Ryan. Much appreciated. I wired the Nest exactly the same way as my old unit and it seems to work. The blue B wire is in the OB port of the Nest as my system is a heat pump. 

I put both red wires in the Rh and the heating works but haven’t tried the cooling as it’s winter here in Australia and my wife won’t let me test the AC. 

If I was to put one of the red wires into the Rc, would it matter which one of the red wires i put into Rc or is it just for power? 

[MelbaDT]

Hey Rhombus78, 

It should not matter which of the two wires will be placed on RC or RH. These two terminals are just for power. 

Best, 

Melba

[Rhombus78]

I test the cooling yesterday and it seemed to be blowing cool air even with both Red wires inserted into the Rh. 

[Ryan_G]

Hi Rhombus78,

Thanks for reaching out here in the Google Nest Community.

I'd like to jump in here and check on how your Nest Thermostat is doing. If it is still having the same issue, could you tell us if you have a dual fuel or dual transformer system?

I hope to hear from you very soon.

Thanks for your help, Melba.

Regards,

Ryan

[Ryan_G]

Hey Rhombus78,

I just wanted to follow up and see if you're still in need of help. Please let us know as we would be happy to answer any questions you may have. 

Best regards,

Ryan

[Rhombus78]

Not sure if it’s a dual fuel system. All I know it’s an electric carrier heat pump.

all seems to be working well. 

[Ryan_G]

Hey Rhombus78,

Thanks for the update.

It's great to hear that it is working well now. If you have further questions, don't hesitate to reply to this thread.

Regards,

Ryan

[Ryan_G]

Hey folks,

I just wanted to follow up and see if you're still in need of help. Please let us know as we would be happy to answer any questions you may have. 

Best regards,

Ryan

[Ryan_G]

Hey there,

Thanks for being here in the Google Nest Community. 

I'd like to bump in here and make sure that you’ve seen our response.

Please let us know if you have any other questions or concerns as I will be locking this thread in 24 hours.

Have a great day.

Best regards,

Ryan