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Noritz NH150-DV

alex41203 Member Posts: 1
Hi everyone. I have a Noritz tankless boiler in my house. Model# NH150-DV. I had it installed about 3 years ago. Recently I started hearing a whistling noise. I only hear it when the heat does not turn on a lot. It makes that noise for about 5-10 minutes and than it goes away. Does it need any maintenance or it’s an issue with the boiler. Any tips please. Thank you in advance!!!


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    All those mod con boilers should have yearly maintenance, which is mainly cleaning the heat exchanger, and checking the combustion quality/condensate drain, etc.
    The installation manuals should detail what needs to be done.
    Has it been function well otherwise? You could check to see if the intake, exhaust, and condensate drain are free and clear while waiting for service.—NBC
  • NY_Rob
    NY_Rob Member Posts: 1,370
    If the combustion mixture has drifted from factory (or commissioning) settings it can produce harmonics.
    If you don't address it... it will eventually fail to start... probably on the coldest day of the year or over a holiday weekend.

    You need to find a tech who is familiar with mod-con boilers and has a combustion analyzer so he can tune it after cleaning/flushing the heat exchanger.