Hi,

I just bought one of those new programmable thermostats. The old one did not have a C-terminal in the thermostat or the wires to the thermostat.

MY HVAC system has Y, R, W, G, C wires in the terminal block. On the new thermostat, and on the HVAC system, I'm connecting the G line to C to power the system. So far so good.

The G line is for the Fan. With the connection above, I lose control of when I decide to run the fan.

I think I can add a manual switch in the hvac to manually turn on the fan if I want to circulate the air in the house. My question is, how do I do this? Which terminals in the terminal block can I wire to a switch to turn it on whenever I choose to?

Thanks for your help.