If you do, you have to replace the wall tstat also, with the one designed for the 2 speed furnace. It is NOT new, it has been out for years. Due to cost, very few OEM's use it. It is usually on the higher end 5th wheels. Since you can only use the Atwood wall tstat, that means in most applications you would not have 1 tstat for Furnace and AC operation, but 2 wall tstats. Doug