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One of my hvac dampers is stuck open

Damper that controls upstairs air flow is stuck open. is a honeywell system installed in 1993. 2-zone system.

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RJ Systems (Retired)

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Zoned forced air systems that use multiple thermostats that can start a single heating and cooling unit from each stat and condition just that space that called it, are conditioned by the auto damper you are referring to. These dampers are normally spring closed and driven open using a small 24 volt motor (Called an Actuator or Operator) connected to the stat that operates the damper motor with a relay. Disconnect the damper crank arm and linkage between the damper and its motor and see if the damper rotates closed. See if the damper will move freely. Power and remove power from the motor to see if it works. Doing these things will probably find the problem. Good Luck. Roger

Posted on Apr 27, 2014


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If you need further help, reach me via phone at

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