Outside temperature sensor and aux heat mode

[Jbloomer]

Hello-

I previously had an older generation of nest thermostat and had to remove due to compatibility issues with new my HVAC equipment. I’m curious if the newest generation (4) will work with my new setup. 

Here are the issues I had with the old nest:

1) The outside temperature was based on zip code / internet weather not conditions at my house.  I live in an area that can have large geographic temperature swings. My HVAC equipment has an outdoor temperature sensor that I would like the nest to use when deciding to use the heat pump or LPG burner NOT Internet weather. Does the new nest accommodate HVAC systems that have a built in outdoor temperature sensor?

2)  The nest I had would not allow me to tell my HVAC to use the LPG burner instead of the heat pump. When I’m on generator power, I do not want my heat pump to run. This is accomplished with Aux/Emergency Heat mode on other thermostats, but my nest would not do it. The HVAC installers said my system would failover automatically when my house temperature did not rise when calling for heat, but this did not happen and I needed to change out my old Nest. Does the new nest allow for aux/emergency heat mode?

Thank you for reading and posting!  This information has been very hard to find answers to!

[Derickf]

Hi @Jbloomer,

Thanks for reaching out to the Google Nest Community. I'm sorry to hear that you are having compatibility issues between your Nest thermostat and your new HVAC system not turning on the emergency heating; don’t worry, help is here.

Answering your question about the temperature sensor: the Nest Thermostat can only be controlled with a Nest Temperature Sensor. 

And about the auxiliary heat issue, I have some questions:

• What type of Nest Thermostat is your old one?
• What is the brand and model of your new HVAC system?

In the meantime you can take a look at the following article: Heat Pump Balance.

I'll be waiting for your response.

Best regards,

Derick.