Heating, Air Conditioning, Fridge, HVAC/Burner won't light


I have a older freedom 80 furnace made by american standard. Model ADD040C924E0.It will not start when there is a call for heat. The blower starts, but not the burner. I see it start to glow then it shuts off, but the blower keeps running.If I go down and shut power off for a few minutes then back on it will start up and run as normal. I am getting 4 blinking lights on the board for a limit switch. I have checked continuity of the switches I can identify and they are all closed. I took the filters out in case that was an issue. They were new, but it doesn't solve my problem. What should I be looking at to figure this out? Thanks

There is a circuit board that works each component on a call for heat. First as you saw the glow coil starts, after the board " Proves " the coil is glowing it opens the pilot or main gas valve to ignite the gas. After the heat exchanger heats up the blower will energize. There is something tripping either a safety or this board is defective. When you turn power off and back on it resets everything. A failed safety typically will not reset but the board will, so in my opinion it is the board. I do not have the codes for this furnace but you can usually download a manual based on the model and serial number to check what this code is indicating. 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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