How to Repair a Johnson Controls Metasys VMA Controller

Stromquist & Company‘s Dozier Mills shows you how to repair a Johnson Controls Metasys VMA Controller.


6 Responses

  1. EXCELLENT VIDEO….Well done Mr. Mills. If you are working with these actuators this product looks like the “THING” to have in your trucks parts bin.

  2. good morning,
    we have vav johnson Valves on our Metasys system for our heating and cooling. Every winter A section of an office get real hot. how can i correct this?

  3. I would send a tech to the VAV Box feeding the hot office to make sure VAV Damper shaft is moving when you command it open or close. If the damper does not move. Then you may have a broken gear > VMA bushing inside the VMA Controller.

    The Video is showing how to change the VMA Bushing.> We sell at

    If the VAV Damper shaft moves when you command open or close.
    Then Tech would nee to make sure the damper blade has not broken off inside the VAV box.

    The Hot office may not be getting the air flow that is required.
    Tech should have laptop and cables to check the VAV Box operation.

    Make sure Supply and Return grills are not close together. This is a common problem found in drop ceilings.

    Good Luck

  4. JCI tech here…. adding this link to an Austin/Dallas email. I hope you’re still selling them!

    Reminder to JCI techs: changing an old VMA with a modern VMA counts as a 3rd-party device and knocks down the number of devices you can have on your trunk:

    *The maximum is 50 Metasys MS/TP devices including FECs, VMAs, and IOMs. The maximum number of (Metasys and/or third-party MS/TP) devices that can be connected when one or more TEC26 thermostat, variable speed drive, or third-party MS/TP device is connected to the FC bus, is 32 devices.

    ie – fix, don’t replace!

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