Thermostat advanced automation

Hi
I want to turn on the AC fan when the upstairs temperature is 2 degrees higher than downstairs temperature.
How can I automate this?

We have one return vent, making the upstairs hotter than downstairs. So I want to turn on downstairs fan to push that heat downstairs

Is you AC fan part of a HVAC control or an independent switch? If it’s a switch you can look at something like this: [RELEASE] Attic Fan Smart Ventiation which handles cooling based on temperature differentials.

Otherwise for a custom setup you may want to look into WebCoRE. It has a slight learning curve but is very flexible.

As stated WebCoRE will do this, I have had this setup for years, it does help keep upstairs and down stairs closer together.

Thank you for your reply. Can you share your code? It will be helpful developing mine.

Thanks
Sharath

There’s some extra stuff in there, like a variable for average downstairs temp. but it should get you started.