Hey Yvonneebrown,
Sorry for the delay here but thanks for posting and welcome to the Google Nest Community.
Just to confirm, are you unable to see your Nest thermostat on your Nest app if using your new phone? If yes, are you logged into your Nest app using the same email address you used to set up your thermostat? Also have you tried logging out, force closing the Nest app, reopening it back then logging back in if it makes any difference.
Best,
Melba
