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Gianonni Coffee Grounds....

kcopp Member Posts: 4,432
We have had this discussion from time to time here about the Coffee grounds that appear at the bottom of the Gianonni HX in the munchkin, Smith GT, Cadet, etc boilers. Anyone have anymore insight?
I have this Smith GT 150 that I installed in 2008. LP gas. Runs a radiant floor and panel rads w/ an 80 gallon indirect.
The combustion numbers are w/in the specs that Smith suggests. Every year I get a good 1/2-3/4 cup of this junk at the bottom...I don't see that on other SS boilers.


  • Tom_133
    Tom_133 Member Posts: 884
    My two cents, I have this same problem on one job and every year I go back and clean it or it won't run through the winter. This job is a carpenters shop, it is direct vent, but it sees a lot of dust. Last year I went to the job cleaned the boiler and told the worker to seal the boiler room up better, to keep some saw dust particle out. He did it and this year I went back to clean it preventatively and found the coffee grounds were a 1/4 of normal. Another job that had the coffee was one across from a corn field, and during harvest season when particulates are high it seemed to fill that HX fast. These are my thoughts, if it's happening on particular jobs maybe there is a cause, if it happens only on LP jobs maybe combustion.
    Montpelier Vt
  • kcopp
    kcopp Member Posts: 4,432
    I would more than likely discount the contamination. The intake is 10 feet off the ground and the exhaust goes through the roof. The house is in a wooded area but not right in the woods.

    Combustion... According to the manual the specs they are fine.
    Here is what I have w/ the boiler in High fire... LP gas
    CO2 10.3, Co 27ppm, O2 5.8 Ea 37
  • Ironman
    Ironman Member Posts: 7,376
    Nature of the beast.
    It seems the only thing that HAS been confirmed about the coffee grounds is that the more the boiler condenses, the more coffee grounds.
    Since we want the boiler to condense as much as possible for maximum efficiency, it looks like more coffe grounds are inevitable.
    I personally believe that the grade of stainless used in the Gianonni is more susceptible to corrosion than some others.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • hot_rod
    hot_rod Member Posts: 22,143
    even pollen sucked into the unit will contribute to that build up. It may look or seem like it's inhaling fresh country air.

    Some of the early Polaris units shipped with a large intake air filter, maybe they still do. After a season of running you see exactly what is in the air stream in the filter.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • kcopp
    kcopp Member Posts: 4,432
    I designed the system design temp to 155 @ -10F... radiant panel rads and radiant floor..... it condenses.