Furnace never turns off

All, The Furnace is located in the crawlspace (Rudd from 1988). It seems in the winter when I have the heat on the furnace will work fine. When the heat light on the thermostat turns off the fan continues to run. The Fan switch on the thermostat is set to Auto. It will stay on for an average of two to four hours or longer. I would like the the fan to only stay on for five minutes then turn off. I do not want to waste so much electric running the fan.
Thanks
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You really aren't using that much electricity by running the fan all the time, but it sounds like you have one of the Ruuds that had a fan timer on it (brings the fan on and off on a set time instead of being controlled by a fan limit switch). I have had several of those "stick" on before. Not sure if you can still order those or not......
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'All,         The Furnace is located in the crawlspace (Rudd from 1988). It seems in the winter when I have the heat on the furnace will work fine. When the heat light on the thermostat turns off the fan continues to run. The Fan switch on the thermostat is set to Auto. It will stay on for an average of two to four hours or longer. I would like the the fan to only stay on for five minutes then turn off. I do not want to waste so much electric running the fan. Thanks'
ME: If your furnace has a Fan /Limit combo control on it, then, the fan portion of the control needs adjusting ; over time, they drift out of adjustment. Moving the adjustable levers inside the control will change when the furnace shuts off after the heating cycle. Move the 'off' lever to a higher temp setting on the control . If that doesnt work better for you, then replacement is necessary.
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'All, The Furnace is located in the crawlspace (Rudd from 1988). It seems in the winter when I have the heat on the furnace will work fine. When the heat light on the thermostat turns off the fan continues to run. The Fan switch on the thermostat is set to Auto. It will stay on for an average of two to four hours or longer. I would like the the fan to only stay on for five minutes then turn off. I do not want to waste so much electric running the fan. Thanks'
ME: If your furnace has a Fan /Limit combo control on it, then, the fan portion of the control needs adjusting ; over time, they drift out of adjustment. Moving the adjustable levers inside the control will change when the furnace shuts off after the heating cycle. Move the 'off' lever to a higher temp setting on the control . If that doesnt work better for you, then replacement is necessary.
Hey, Prevert, I've never seen the Fan/Limit 'drift.'
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'Hey, Prevert, I've never seen the Fan/Limit 'drift.''
ME: Doesnt surprise me . They do. Next time....check the fan/limit when you clean a furnace.
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I always check the Fan/Limit, providing it's not a control board. It's part of the service routine.
The only way they move is someone adjusts it.
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