FAQ - Campus Users

    HVAC Air Handler Unit (AHU) Freeze-stat Reset Symptoms

    The freeze stat is to prevent the freezing of the air handler coil. If the temperature from the outdoor fresh air duct becomes low enough to freeze the coils. This can happen if the outdoor air temperature is very cold and the air handler blower is not running because it's in an unoccupied mode. The hot water valves are opened fully to heat up the coils. The web control system might intervene with other techniques. Ask Todd about these sequences.
    1. 1

      ALC Sends Email that a freeze-stat has tripped

      Go to the unit identified
      Verify the outdoor air damper is closed
      Press the black button on the clear plastic control box located near the return air duct.
      After it is pressed you will hear the fan motor start-up and things should be normal.
    2. 2

      Noticable Symptoms

      Some LC rooms may overheat uncontrollably.
      One instance on 2/8/24 @ 5:30pm: The center second floor hallway is 78°, room 203 is 77° and room 204 is 78°. The setpoint in these rooms is currently unoccupied and at 64°. The other classrooms are working properly. I am not sure Why they are overheating. After the freeze stat for AH3 was reset the temperatures returned to normal. Todd checked the system and could find no problem. It seems like it is just one of those tech things.
    3. 3

      Freeze stat Locations in LC and Main Street

      LC/AHU 1 & 2: are located in the basement mechanical room adjacent to the Great Hall.  The entrance is on the left hand side of the hallway near the janitorial closet.


      LC/AHU-3: Located on the Second Floor near the water fountain. It is in the hallway mechanical room between the two janitorial closets.  

      Main Street AHU 4: Located in the mechanical room in the main hallway.  The entrance is between the double wooden doors near the Women's and Men's bathrooms. Once in the room, the button is located to the left across from the 4 water pumps.








    4. 4

      Barnabas Event Tuesday, Jan 10, 2017, 4:12 PM

      (This might have been the legacy stat which was replaced and tied into the WebCTRL) "The freeze stat will trip around 5° outside and that stops the air handler from running but it opens the boiler valves to full heat. Most of the time when this trips it resets because it has an automatic reset and there's really nothing wrong with the system other than you have a little leakage around the damper for the fresh air intake."
    5. 5

      Office/Activity FreezeStat

      One is located in the attic on the fresh air blower system.
    6. 6

      Sanctuary freezestats

      One is located on the fresh air intake in the boiler room or the room directly to the west (Hamilton Ave side) of the room.
    7. 7

      Sanctuary Choir Fresh Air intake

      This freeze stat is located in the ceiling above the east, rear Access Ramp Door hallway.
    If you still have a question, we’re here to help. Contact us