Have HVAC Questions? Ask an HVAC Expert for Answers
Are you using a single stage or two stage thermostat?
1. Give me model on thermostat
2.Tell me what wires are connected to what terminals at thermostat
3.Tell me what wires are connected to what terminals in furnace.
The reason I need to know this in order to answer your question is that the furnace operates differently depending on which you are using. If using a two stage thermostat, thermostat decides when second stage heat is initiated and if using a single stage thermostat, furnace control board decides.
Tell me what terminals on thermostat those red,white,black and green connect to
The operation of the thermostat is determined by how long it runs. Usually with respect to outside temperature. The thermostat remembers trends in running. High stage can be as little as 2 minutes or as high as 11 minutes before it kicks in. Trane and American Standard run about 9 to 10 minutes before it goes into high stage Russ
Sorry I had an emergency and could not get to phone till 2 am central time. Can not understand why they converted to high speed. Does furnace come on low fire when starts up. Russ
Call me today 9 o'clock CDT. Russ