I changed out a furnace and AC with an existing nest. Started up the new system in cooling mode. Only the condenser pulled in and not fan on the furnace. 4 wire set up with typical RWGY. Fan comes on in heating mode. Do I need to pull a common up to the nest? Jumped from R to G on the furnace board to get a temporary fan in cooling mode.
Thanks for reaching out and we're sorry for the delay.
This is one example where we need to have a C (common) wire connected to your Nest Thermostat. We could use the Nest Power Connector if you don't have an available common wire from the HVAC unit.
We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the Community.
