Replacing Aprilaire thermostat with nest

[Heathcat]

 

I replaced my Aprilaire 8465 thermostat with a Nest Learning thermostat. I inserted all of the wires correctly (I thought) but it on blew out hot or luke cool air (as I installed the temp went from 67 to 74 and then never got back down past 75 in almost 2 hours). I followed the Nest install video. There are 2 wires going to the Y connector on the original thermostat so I placed them in Y1 and Y2 respectively. Any advice or just incompatible?

[CoolingWizard]

The second wire in the Y connector is not Y2.  Y2 is for stage 2 and you do not have that.  You will need to go to your indoor air handler, open the cover, and see were that brown wire is going.  Only then will we be able to determine the proper location.  Heat Pumps are manufactured in two default modes.  They are Type O and Type B. Type O models are Heat by default.  If the reversing valve coil fails, you will still have heat and no cooling.  Type B models are air conditioners and if the reversing valve coil fails, you have cooling however,  no heat.  If the outdoor air is 75°F or warmer, you can test cooling.  If you start a a cooling test, you feel cold air wishing 5 minutes. If the air comes out warm or even hot, your OB wire mode needs to be changed.  The Nest defaults to setting heat pump mode to type O since 80% of heat pumps sold are O models.  Rheem and Ruud are always B models.  

AC Cooling Wizard

[Jenelyn_O]

Hi everyone,

Thanks for posting in the Google Nest Community forum. I just want to check if you managed to see the response above. Please let us know if you still have questions or concerns, as we'll be willing to assist you further. 

I appreciate your help, @CoolingWizard.

Best,

Jenelyn

[Jenelyn_O]

Hi Heathcat,

I wanted to follow up if you still need help. Please let me know if you’re still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Thanks,

Jenelyn

[Jenelyn_O]

Hey Heathcat,

Due to inactivity, we'll go ahead and lock this thread in 24 hours. We'd be glad to help you further so if you still need assistance, feel free to start a new thread.

Regards,

Jenelyn