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Futura III Combustion setup MB1500

Bill_69 Member Posts: 12
Any help or tips on how to properly set low and high fire on this modulating boiler?

The IOM mentions a gas adjustment to set low fire (33%) maintaining close CO2 and O2 range. Book then gives recommended CO2/O2 range in high fire (100%), but no mention of adjustment procedure. Also, how close do the numbers have to be per their book. Ex. book wants 6.2% O2 in high fire- is 6.9% too high?

Thanks in advance


  • Tim McElwain
    Tim McElwain Member Posts: 4,608
    I looked at the I and O manual and it is not

    really clear I suggest you call them:


    260 North Elm Street

    Westfield, MA 01085

    Phone 413-568-9571

  • HydroMan
    HydroMan Member Posts: 14
    Futera III setup


    You have to look at CO2 setting in high fire and then adjust the damper blade at the fan on the inside of boiler, then you have to make small adjustments on the low fire side using a 1/32"(?) allen wrench at the front face of the main gas valve to dial in the low fire CO2. Hope this helps.
  • Bill_69
    Bill_69 Member Posts: 12

    Thanks for the help. I was having a hard time keeping consistent combustion after adjustments. Tech support said the burner is probably dirty. Recommended cleaning is 1-2 years.

    I have to remember that these high efficiency units need more maintenance than the old ones.
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