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Beckett Riello air tube insertion debts vary?

Jack M
Jack M Member Posts: 223
Burnham specs several burners for this MST396
The insertion dept for the air tube on the Riello burner is 10" yet the insertion depth on Beckett (L retention head) is only a few inches. Why such a huge difference in the insertion depth?



  • hvacfreak2
    hvacfreak2 Member Posts: 500
    That difference does seem radical. 10 inches places the burner head in the center of the chamber , or pretty close. It might be worth the call to the factory to confirm that dimension.

    Mechanical Enthusiast

    Burnham MST 396 , 60 oz gauge , Tigerloop , Firomatic Check Valve , Mcdonnell Miller 67 lwco , Danfoss RA2k TRV's

    Easyio FG20 Controller

  • Jack M
    Jack M Member Posts: 223
  • rick in Alaska
    rick in Alaska Member Posts: 1,452
    Some of the Buderus boilers spec'd the insertion pretty deep also. Looked weird to see the burner so far in to the chamber, but they worked well. I think it had to due with turbulence in the firebox, which was basically blowing the flame right back at itself, and causing some burnt firetubes. For some reason, now they seem to be back to conventional depth.
  • Jack M
    Jack M Member Posts: 223
    edited April 2016
    I found the spec for the Becket insertion depth (2"). Nothing close to 10". The Riello's retention head is not on the very end of the air tube (like the Beckett) but still. Burnham does this (deep Riello air tube) on the MPO and MST but not in every size.

  • Jason_13
    Jason_13 Member Posts: 304
    Has to do with positive pressure and getting the boiler to fire. I remember they really hesitated coming out with Riello and I believe the reason that Riello had a hard time getting the boiler to fire and run properly.
  • Jack M
    Jack M Member Posts: 223
    The few times I have come across a gas conversion burner (Carlin) on MPO and MST Burnham boilers they have also had deep inspection depths (12 -14") . Be a good question for FireDragon if anyone is taking his class. He seems to know his way around Riellos.
    Some of what Jason said might explain why Burnham never offered a F-3 for the smallest MegaSteam (MST 288).