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natural gas boiler rusted inside

shancf Member Posts: 1

Hello everyone, I happened to notice rusted inside today. This is basically a newly installed boiler. cannot believe seeing rusted parts in such a short period.

Need help to understand:
1. what could cause this?
2. how bad is this? need replacement?

Thanks in advance!


  • Jamie Hall
    Jamie Hall Member Posts: 23,456
    Any one of a number of things can cause surface rust like that. If it being run condensing for any length of time, and it is not designed for it that will do it -- but it could also be just from sitting around.

    And, no, it shouldn't need replacement or even any concern, unless there are spots which are much worse than the photo.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • JimP
    JimP Member Posts: 87
    It looks brand new. Was the casting stored in a damp environment or did it get rained on before installation ?
    EBEBRATT-Ed Member Posts: 15,635

    Have the flue gas temperature checked when it is next serviced and also have the return water temperature checked (I am assuming this is a hot water boiler). Flue gas condensation can cause rust.

    The rust in the picture appears normal but it would be worth getting those two items checked at some point. just to be sure you don't have any issue.
  • gyrfalcon
    gyrfalcon Member Posts: 165
    Looks normal to me.  Imagine a cast iron pan that never had grease or cooking oil applied. Just heating up and cooling down on your stovetop. It would eventually get rusty too. 
    Slant Fin Galaxy GG100(1986) , 2 zone hot water baseboard, T87 Honeywell thermostats.