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Rheem control board burning out

I have a Rheem Criterion II.   It had a Honeywell ST9101A 1014 control board.  It burned out.  I replaced it with a Honeywell ST9120U1011 (the universal replacement suggested by Honeywell).  That board burned out as well.  I turned on power to the heater and that's when it burned out.  No fans came on or anything....just smoke from the board.  My question.....what is causing this board to burn out ?


  • Ironman
    Ironman Member Posts: 7,119
    Check Your Shorts

    Obvously, you have something shorted. You need to call a pro. This is not something you can be "talked through".
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Tim McElwain
    Tim McElwain Member Posts: 4,588
    The ST9120U board

    has a fuse on the board. Did the fuse blow or did the board fail without blowing the fuse? Seeing you have replaced the board yourself, take it out and look at the back of the board and see if there is any evidence of the printed circuit being burned. 

    If so I would suggest you take Ironmans advice and call a pro. Those boards are not cheap so I am sure you do not want to burn out another one.
This discussion has been closed.