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Proper Riello F3 for use with outside combustion air

Brent H.Brent H. Member Posts: 83

So my contractor is starting tomorrow to install a new 3 section Buderus G115WS in my basement but we've gotten a bit of conflicting information from supply houses and Buderus. For the install, I asked him to make sure the burner will support a connection for outside combustion air. The supplier told him that the Riello BF3 burner was needed. He then talked to Buderus and was told that the BF3 is meant for direct vent applications and we should use the F3 which now has a knockout for outside air. Looking tonight at the manual for the F3 in the spare parts drawing, the ducted combustion air intake kit(part#3002761)is shown with only a checkmark next to it in the F5 column, not the F3. Is the kit only valid for the F5 or does it just not come standard with the F3? Has anyone used a F3 burner with outside combustion air?



  • R ManninoR Mannino Member Posts: 422
    The F3

    that comes with the G115 has the knockout. As long as it's not old stock.
  • Brent H.Brent H. Member Posts: 83
    4" Adapter

    Have you been buying the adapter from Reillo or just using a standard stick-on one? Do you block the stock air intake in the cover or leave it open?

  • Robert O'BrienRobert O'Brien Member Posts: 2,938
    edited November 2011
    Sealed combustion?

    If you want sealed combustion,you need a BF. If you just want to use outside air,the standard knockout and collar is the cheapest. EK makes a nice adapter that doesn't need to be removed every time you take the burner cover off
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • Brent H.Brent H. Member Posts: 83
    Outside Air

    I'm mostly just trying to reduce infiltration a bit. It's funny, one person at Buderus told me that the BF could be used but a savy tech. was needed to setup the burner. Another person at Buderus told me you couldn't use the BF with a chimney...... they need to get their stories straight. We actually have both burners at the house since we weren't sure which to use. In the end, I'll probably just use the F3 since it's all setup for the chimeny vent boiler.

    I'm still curious if the Riello kit for adding outside air includes a plate to cover the vent in the cover.

  • Ron Jr.Ron Jr. Member Posts: 527
    edited November 2011
    I had a BF3 on my standard oil boiler

    for years without an issue . It was ducted to the outside with 3 inch PVC . I'm not sure of the noise level with the newer F3 covers ( if it's ducted to the outside ) but the BF3 cover is extremely air tight and cuts the noise down considerably . Compared to a regular , unducted F3 .

    I have a Beckett NX now ( like in Bob's 2nd pic ) and it's even quieter than my old BF3 .
  • R ManninoR Mannino Member Posts: 422
    We Prefer the NX for Outside Air

    It's easier and quieter too
  • David107David107 Member Posts: 1,193
    edited December 2012
    vac breaker or not

    Seems that the old stock F3s without the cutout can have a hole cut out--but they lose UL certification.

    Techs at Buderus and Riello have different takes on vacuum breakers on the intake. Buderus recommends a vacuum breaker near the entry point from outside to help warm the air and a Fields hood with a varmint screen.  But Riello says vacuum breaker not required since the F3 is not completely sealed like the BF. They say not to block the stock air intake in the cover with the new line. So then the burner would be getting some air from both the new intake and the built-in one so there would still be air seepage but maybe less.

    Riello also says cold air doesn't cause problems with the oil. Interesting divergence of

    opinion. I know many on these forums ARE concerned with cold air on oil. One site strongly recommends a twenty-foot run inside the basement to warm up the incoming air. Any thoughts?

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