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Short cycling

am7315am7315 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?


  • am7315am7315 Member Posts: 2
    Is it ok to add a return vent near furnace on the return side?
  • mattmia2mattmia2 Member Posts: 2,301
    no and no.
  • Jamie HallJamie Hall Member Posts: 14,836
    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.
    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • JUGHNEJUGHNE Member Posts: 7,867
    How is the air filter?

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