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Heating, Air Conditioning, Fridge, HVAC/Lennox air conditioner (package unit)


When I cut the air conditioning system off the fan continues to run.  What can cause this problem, and what might I do to correct the problem?

You did not say but my guess is the heat is some type of fuel heat and this is not a heat pump. With fuel heat, the fan is delayed until the heat exchanger heats up. The fan is energized by either a timer or temperature sensor and if this part fails the fail safe mode makes the fan run all of the time, so this would be the first part I would check. It will be indentified on the wiring diagram of the door panel. Even if the unit is a heat pump there is a fan relay to bring on the fan and this could be the failed part. Thanks J

Heating, Air Conditioning, Fridge, HVAC

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J Cook


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.


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.

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