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Chimney liner questions

bmac_to Member Posts: 2

Three years ago I replaced a 80 year old oil boiler with a Viessmann Vitola NG boiler (with a lot of advice from this website).  Everything concerning the boiler has been great.  However, the chimney cap (sometimes called crown) is starting to disintegrate. 

Some background info - the chimney is about 10 years old so having the cap disintegrate is premature.  The cap is a precast concrete type.  The current chimney liner is a stainless steel liner that was left over from the oil boiler - it was quite new and the contractor who installed the boiler did not feel it was necessary to change it.

I think there are one of two possibilities for this premature failure - the cap was installed incorrectly (wrong mortar, etc), or it is directly related to the new boiler.  Due to the lower exhaust temperatures of the new boiler, perhaps condensation could be causing this problem?

What is everyone's opinion?  If it is condensation, whould replacing the liner help?  If so, what type would you recommend?  Aluminum?  Insulated stainless?  Other? 



  • Tim McElwain
    Tim McElwain Member Posts: 4,574
    edited April 2010
    It is quite possible that

    due to low flue gas temps you are condensing in the chimney. I would suggest getting a chimney professional and have the liner extended to the top of the chimney with a stainless steel cap.
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