Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit

ultra 155 cycles on and off repetitively

Brotherhr Member Posts: 1
My boiler sounds like it is turning on and off over and over all night sometimes. It makes heat though.


  • Jamie Hall
    Jamie Hall Member Posts: 16,606
    Most likely a control problem -- or a wildly oversized boiler with no buffering. But we need a lot more detail on the system -- system size, boiler size, piping, controls...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    JUGHNE Member Posts: 8,685
    When was it opened up and serviced last?
    Failing flame sensor has those symptoms.