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Clanking boiler

I'm looking for someone who can explain this problem and offer suggestions as to how to address it.

My old (installed 1954) cast-iron boiler has, in the last year or two, started making clanking sounds when it heats up. We've lived in this house for 22 years with this system and this did not occur until the last couple of years.
We use setback thermostat so that the system is idle (and cools down) until the call for heat comes.
The problem is annoying but mainly I am worried that some damage might be being done to the boiler, and now would not be a good time for me to replace it.



  • Couderay
    Couderay Member Posts: 314
    Clanking boiler

    More info needed. Is the boiler hot water or steam. When was the last time this boiler was serviced. If it has been a few years do yourself a favor and get it serviced before ol man winter comes a knockin.
  • Eric Peterson_3
    Eric Peterson_3 Member Posts: 55
    Clanking boiler - help! - More Info

    The boiler is hot water, atmospheric venting, closed loop.
    Single pump, pumping away, with three zones (zone valves).

    The boiler is cleaned (burners, passages) every year.
    What other service did you have in mind?
  • Clanking boiler

    Interesting description, could be anything.
    Do you mean a popping(like popcorn) type sound?
    It could be time for a complete wet side system cleaning.

This discussion has been closed.