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Removing baffles requires changes in combustion settings?

D107 Member Posts: 1,849
"...Adjusting the baffles 45 degrees will increase the stack temperature approximately 20 degrees, removing them increases approximately 40 degrees and the removing the flue gas blocking plate will increase the stack temperature approximately 50 degrees. Removal of both will result in an increase of approximately 90 degrees. If condensation is occurring in the chimney would be reason to adjust or remove the baffles and plate."

EDIT: So I guess the plate removal would make sense, probably subject to the same combustion issues raised by Paul in his post.

The only additional thing I'd note here is that I don't have proof that condensation is occurring. The SS liner was insulated the Thermix, but probably less than an inch all around, and the consensus seems to be follow the factory specs. 270-300 degrees is quite a low stack temp.

If there was condensation, I don't believe (not qualified to say) it would drip into the boiler given the T into the breech, but the liner itself would likely deteriorate over time. I guess I could have the chimney top inspected. I'd much rather do all this at the next tuneup....

Thanks for your response,



  • D107
    D107 Member Posts: 1,849
    Riello F3 40/buderus G115/21, 5\" SS chimney liner

    Annual Tuneup this fall left stack temp at 300; should be 350. I re-checked stack temp on my own a month ago, got 270deg. Obviously baffles should be removed. I don't want to see SS liner damaged by condensation. (chimney external)

    Anyway, removing them should require another combustion check--is there anything in particular that could be expected to change from this action? (Aside from slightly lower efficiency.) Trying to make sure tech does a thorough job on this.

    Nozzle (Delavan): .50 x 80o B; air gate: 2.25; pump 155psi; turb: 0


  • Paul Fredricks_3
    Paul Fredricks_3 Member Posts: 1,557

    Removing the baffle could change the draft reading over the fire, which in turn can cause more air to be drawn into the fire. That would drop the CO2 reading, could change the CO reading. Any work that is performed on the unit that could change combustion must be tested, per code.
  • jim burke
    jim burke Member Posts: 26

    David why remove the baffles when you can just open up center baffle plate . This will raise stack temp.You take set screw out and remove and flip it over so center flue will be open.
    Buderus manual will show the location of this baffle.
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