Hi @Mal5,
Thank you for posting in the community. I understand you live in a three-story home, and the upstairs will not cool down, keeping higher readings than the lower levels. I'm happy to help.
Could you please tell me if your Nest Learning Thermostat (4th gen) is displaying any error message?
Based on what you mentioned, I recommend you contact a technician to verify the cooling system's distributions. Depending on where your system is located, it could be normal to have lower readings in the levels closer to it.
It's really important to mention that the distributions of your system need to be well installed throughout the house in order to get the desired readings.
Please keep me posted.
Regards,
Anders
