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Buderus G115/4

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duh
duh Member Posts: 21
in Oil Heating

Greetings…I just had a new Buderus G115/4 with a Riello burner installed. I don't know much about this stuff, but I am questioning the results of the combustion analysis and would like to get an opinion before I call them back.

This is the reading from the installer:

O2 = 5.4%

CO = 26 ppm

Fluegas Temp = 418.2 F

Eff = 85.5%

Ambient Temp = 102.4 F

Excess Air = 32.4%

CO2 = 11.65%

Undiluted CO = 35 ppm

I'm questioning:

1) the fluegas temp. If that's the same as "stack temp," I believe Riello specs indicate approx stack temp as 326 F, right? Are my results ok?

2) the CO on my old G115/4 was 4 ppm. Is this new one at 26 ppm ok?

3) I thought the "ambient temp" meant the temperature in the air. Maybe not? But it was installed 12-11-25 and it sure wasn't 102.4 F in the cellar. Does that make a difference in the combustion analysis overall?

Two other things not related to the combustion analysis:

1)when the boiler goes on, I hear a bang. It's not really, really loud, but it's loud enough that I've looked out the window on several occasions to see if someone just drove up and they slammed their car door shut, and then I realize it was the boiler that just went on

2) when the boiler is running, the air rushing through it sounds loud. It's much louder standing in the cellar, of course, but also sounds loud (or louder than I'm used to) when I'm upstairs. It almost sounds like water rushing when I'm upstairs (and even on the second floor), but it's the boiler that just kicked in.

Could someone comment on this, please? I don't want to call them back and waste their time because I'm overreacting to nuances. I figure there has to be some of you who can look at this and know instantly if something is amiss, or if I'm just paranoid because I know nothing.

Thanks so much, one and all.

duh

Comments

  • Ironman
    Ironman Member Posts: 7,874
    edited December 16

    The ambient air is subtracted from the flue gas to get the actual stack temperature.

    IDK why the ambient is listed at 102*, but it’s obviously not accurate.

    Too much excess air will also raise the stack temperature.

    Nothing looks too far off, but a little tweaking could be done.

    What was the draft?

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 11,588
    edited December 16

    The ambient temperature is measured by the location of the actual combustion analyzer.  That may have been placed too close to the boiler or vent connector and be measuring some radiant heat from the appliance or connector.  That can be an oversight by the technician since there is often a magnet on the back of the case for placing the meter directly on the boiler cover.  That is often done on purpose by a skilled technician to inflate the printed combustion efficiency. Since the NET stack temperature is where the efficiency is calculated from.

    Otherwise those numbers are acceptable for a year of operation, as long as the Smoke Spot Number is zero. That is usually a test done with a separate device.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    Big Ed_4Ironman
  • duh
    duh Member Posts: 21

    Thank you, EdTheHeaterMan!

    Good point about placement of the analyzer. I feel better about that now.

  • duh
    duh Member Posts: 21

    Ironman,

    I don't know what the draft is. How do I find out? It was not printed on the analyzer results.

  • Ironman
    Ironman Member Posts: 7,874

    You have to ask the technician who took the readings.

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 19,642

    I am assuming this is oil?

    Your #s look pretty good to me except the 102 ambient is off which could throw the stack temp calculation off as well.

    Everything else looks ok

  • duh
    duh Member Posts: 21

    Yes, this is home heating oil.

    Any idea why there is a slight bang when it goes on?

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