Google Nest Community

I cannot answer your question because I did not need to use the adapter. I found a common wire and connected that to the "c" wire at both ends.

They sent me one for free, however, I didn’t need it in the end

Is the black wire also connected to the c wire terminal at the furnace control circuit board? Mine was not. Once both ends are connected, you should have constant power at the thermostat

Is the black wire connected to the c wire terminal on the furnace control circuit board. Mine was not connected there originally. Once connected, check for power. Mine worked on the first try

Sears. See my previous post above.