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Whistling Boiler

Nilsonov Member Posts: 1
I have a Utica MGB1252 residential forced water boiler that started whistling after a tech replaced the gas valve (replaced to get rid of that valves failed Mercury Flame sensor). After replacement the main burner whistles exactly like in this video (jump to 1:00) - . He couldn't figure out why but and neither can I after researching this for some time. Any ideas?


  • JohnNY
    JohnNY Member Posts: 2,761
    You need to take a manifold pressure reading and set it right, usually 3.5" w.c.
    Contact John "JohnNY" Cataneo, Master Plumber
    in New York
    in New Jersey
    for Consulting Work
    or take his class.
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,307
    Yes, first place to start on pretty much any gas appliance is set the manifold pressure to spec. That may relieve the noise, then do a combustion setup with an analyzer. Assuming the HX has been cleaned (if applicable). 
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • Big Ed_4
    Big Ed_4 Member Posts: 1,775
    Take the pressure on the supply side at static and while firing as well..
    I have enough experience to know , that I dont know it all