If I'm understanding you correctly, you shouldn't have to do anything. On any call, cool or heat, the thermostat should put 24 volts on the G wire, this is the wire to the furnace that turns on the fan.My furnace (gas) has C G Y W R
Stat itself (digital) has Y RC RH (jumper in place on rh an rc) W G C H2 H1
what I would like to do is use the "cool" function of the thermostat to strictly start the blower. I have no "cooling" in place, I just would like to run the blower on the t-stats "cool" cycle to help circulate the air.
another question, on the furnace circuit board, what two control leads do I "jump" to start the blower?
thanks in advance.
Just hook your 5 wires to the same terminals on the new thermostat. R goes to both RC and RH on the stat.
Jumping R and G at the furnace should turn on the fan.