How do I connect a thermostat with separate leads from the air and furnace?

Question

I have two sets of wires 1 from the air and 1 from the heat (both contain 3 wires)going to 2 round thermostats. I replaced the one to the furnace with a multiple setting therostat. how do I wire the air to the same thermostat?

Answer 1

Way too little information here!

Answer 2

You must use a thermostat that has terminals for seperating the transformers from each unit.

It will have a RH (heating) and RC (cooling) terminal.