Hello Harsh_pat,
It sounds like you're experiencing an issue with your Nest Thermostat where the heat and fan don't seem to be working during testing. While I understand that you don't see any messages on the display, there are a few potential reasons for this issue.
Make sure that your Nest Thermostat is properly connected to your heating and cooling system. Check the wiring to ensure everything is correctly set up. If there are any loose or disconnected wires, reattach them securely. Additionally, check the settings on your thermostat to confirm that the heating and cooling modes are correctly configured. Sometimes, settings may be accidentally adjusted, preventing the system from activating as expected.
If these steps don't resolve the issue, it might be helpful if you could share with us a photo of your old thermostat and Nest Thermostat's wiring setup.
Keep me posted.
Regards,
Mark
