In heat mode after temp reached.HP and it's fan go off,but not house fan. COOL works OK. Have Robert shaw 4220. Removed "G" wire on stat block and fan still doesn't turn off.Thanks Dan...

I believe this is more of a question for the Heating and Cooling forum rather than the Electrical and Lighting.

However, I will hazard an answer for you, only because I went through something similar last Fall.

Check and see if your furnace uses a device called an "Fan Sequencer" or something similar.

This device controls the On/Off of the fan.