https://www.googlenestcommunity.com/t5/Nest-Thermostats/Replacing-Honeywell-with-nest/m-p/711959#M134314 <P>Thanks David!</P> Sat, 19 Apr 2025 11:59:05 GMT Shiraj 2025-04-19T11:59:05Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/Replacing-Honeywell-with-nest/m-p/711910#M134309 <P>I have a Honeywell THX9421R5021WW. It does use wifi. It only has 2 wires &nbsp;R and C. The C wire is white and seems to be powering the thermostat. The R wire is red. I want to replace it with a nest 3rd gen. Is this possible. Thanks.&nbsp;</P> Sat, 19 Apr 2025 03:15:55 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/Replacing-Honeywell-with-nest/m-p/711910#M134309 Shiraj 2025-04-19T03:15:55Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/Replacing-Honeywell-with-nest/m-p/711958#M134313 <P><SPAN>Hi&nbsp;<a href="https://www.googlenestcommunity.com/t5/user/viewprofilepage/user-id/714816">@Shiraj</a></SPAN></P> <P><SPAN>Based on the wiring, it looks like your system is proprietary. Proprietary systems are not compatible with Google Nest thermostats. However, some proprietary systems can be rewired by a Nest Pro installer to be compatible.</SPAN></P> <P><SPAN><STRONG><A href="https://support.google.com/googlenest/answer/9232427?hl=en" target="_blank">Professional installation and service - Google Nest Help</A></STRONG></SPAN></P> Sat, 19 Apr 2025 11:57:32 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/Replacing-Honeywell-with-nest/m-p/711958#M134313 David_K 2025-04-19T11:57:32Z https://www.googlenestcommunity.com/t5/Nest-Thermostats/Replacing-Honeywell-with-nest/m-p/711959#M134314 <P>Thanks David!</P> Sat, 19 Apr 2025 11:59:05 GMT https://www.googlenestcommunity.com/t5/Nest-Thermostats/Replacing-Honeywell-with-nest/m-p/711959#M134314 Shiraj 2025-04-19T11:59:05Z