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Short cycling

am7315 Member Posts: 2
Hello I have a question, I just moved into a house with a 96% hi efficiency that was recently installed by the previous owners and noticed that it was short cycling. There are four red flashes which is a open limit switch. I was able to clear error code by closing gas valve enough so internal temp of furnace was not high enough to trip limit switch. Question is, is this normal or should gas valve be opened all the way all the time?


  • am7315
    am7315 Member Posts: 2
    Is it ok to add a return vent near furnace on the return side?
  • mattmia2
    mattmia2 Member Posts: 7,708
    no and no.
  • Jamie Hall
    Jamie Hall Member Posts: 21,092
    and you need to get a competent tech. out there familiar with that particular unit to service it. Something is amiss, and those high efficiency units absolutely have to be serviced by someone knowledgeable on the particular make and model.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    JUGHNE Member Posts: 10,561
    How is the air filter?