topic Replacing White Rodgers 1F78 with Nest Learning Thermostat Gen3 in Nest Thermostats

Replacing White Rodgers 1F78 with Nest Learning Thermostat Gen3

szewonkwok — Thu, 12 Oct 2023 20:35:23 GMT

Hi there,

I'm trying to replace my old thermostat. My current thermostat is White Rodgers 1F78, and the replacement model is the Nest Wifi Smart Learning Thermostat Gen3. However, I'm not quite sure how should I connect the wire properly, also there's no C wire connected to the old thermostat. I attached a photo to show the wire connection. It would be appreciated if anyone could provide more information about the wire connection.

Thank you!

Re: Replacing White Rodgers 1F78 with Nest Learning Thermostat Gen3

Patrick_Caezza — Fri, 13 Oct 2023 02:54:59 GMT

@szewonkwok

Just match the terminal labels on the original thermostat to the label on the Nest. You can ignore the jumper between RC and RH, as the thermostat will internally make the connection if one is needed.

The Learning Thermostat can operate just fine without a C wire, but I always recommend installing one. You can use a spare wire if there is one or use the Nest Power Connector.

Re: Replacing White Rodgers 1F78 with Nest Learning Thermostat Gen3

szewonkwok — Fri, 13 Oct 2023 19:04:57 GMT

Hi @Patrick_Caezza! Thank you for your reply! I have one more question, should I plug Y into Y1 or Y2, and for W should I connect to W1 or W2?

Thank you!

Re: Replacing White Rodgers 1F78 with Nest Learning Thermostat Gen3

Patrick_Caezza — Sat, 14 Oct 2023 02:17:35 GMT

@szewonkwok Use Y1 and W1

Re: Replacing White Rodgers 1F78 with Nest Learning Thermostat Gen3

szewonkwok — Sun, 15 Oct 2023 06:36:37 GMT

@Patrick_Caezza Got it! Thank you so much XD