adjust fan switch ON temp

Old 10-29-04, 02:50 PM
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adjust fan switch ON temp

I hope this is fairly straghtforward. I would like to adjust my blower fan on a Comfortmaker forced air furnace to "turn on" at a lower temperature than it does currently. I just repaired a Thermo-Mist humidifier and cannot get the new board's heat sensitivity setting "low enough" to keep the unit from turning ON until AFTER the fan goes ON. Right now, the humidifier spray begins about 30 seconds prior to the fan going ON. I know enough to get to the blower motor and oil it but otherwise have not played down there much.


EDIT: I found the switch. It is a Honeywell Fan/Limit switch.
The settings were:
OFF=90 ON=150(max), LIMIT was set at 250(max).
I changed the settings to:
OFF=90 ON=120 , LIMIT set to 150. I understand the OFF/ON settings, but do not know what the LIMIT setting really means. Anyone help me out here?

Jim again.

Last edited by jim-alex; 10-29-04 at 06:26 PM.
Old 10-29-04, 07:49 PM
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You have set it at a good temperature. All of them. The limit is where the burner gets turned off if the fan doesn't work or can't remove heat quickly enough.

Old 10-29-04, 08:53 PM
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Ken - Thanks for the reply. Makes sense.

Old 11-01-04, 01:57 PM
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Location: Mountain Williams Missouri
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I set the limit at the 200o and the fan on 110 or 115 at the most fan off at 95. If the fan blows to cool of air at shut off kick it up . I think 90 shut off is to low and might go on and off a lot . When you just get the furnace started in the first of winter.

My .02 cents


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