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.
I have a G40UH series Lennox furnace that has been acting up. Intermittently the temp will drop below the programmed temp and the heat will not kick on. I have replaced the thermostat and have the same problem. If I turn the desired temp down and then back up or turn the thermostat off then on it the furnace will turn on. Is there anything it could be besides the control board? Thanks!
JR
Answer JR this could indicate a number of problems. Turning the stat down and back up or off and on resets every safety control in the circuit. A failing safety or a safety doing its job and cutting the heat circuit off is very likely. The furnace needs a thorough inspection of the safety devices and the heat exchanger. Thanks J
