AboutJ Cook Expertise With 25+ years experience, I am familiar with residential, commercial, and industrial HVAC equipment including but not limited to boilers, chillers, reciprocating and screw compressors. I am trained in all manners of control wiring.
Experience I currently have three HVAC licenses and Refrigeration license by the State of North Carolina. I have been in this field for over twenty years. I have been a service technician for a contractor and also worked at a state college in the repair and maintenance of steam lines and equipment. I am currently the Building Maintenance Superintendent for a municipality.
Question Im in school for hvac i would like to know if when the thermostat is reading the same temp as the room and cuts off because its on auto why if the fan is on auto it keeps running shouldn't the fan cut off also? please send me the answer as soon as possible i beleive it has to do with the pressure switch
Answer If the heat is a fuel furnace, the fan is not controlled by the thermostat, it is controlled by an internal control, either a temperature switch or circuit board and it continues to run to allow the heat exchanger to cool down. If the fan cut off immediately the heat exchanger could crack. Thanks J
