v8-4 w/ afg becket loud bang on startup

Old 10-21-06, 04:50 AM
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v8-4 w/ afg becket loud bang on startup

I replaced my boiler last year with a burnham v8 and beckett afg burner. My brother-in-law (10yrs as a master) was very familiar with Burnham and seeing how he's the Master plumber I do what he says. (He doesn't tell me how to wire a house.)

I was about a week away from the install and happened to be working on a new construction home (1 million plus )where I met an old curmudgeon who'd been installing boilers in New England for about 30 years. His work was excellent and I could tell this guy new his stuff. I told him what I was up to and what I was putting in and he warned me that there was a conflict between this boiler and the packaged burner, and that it wouldn't run smooth when it got cold out and the draft got heavy. Said he never could get it right after tinkering/replacing for weeks, even after the salesman and Beckett rep came out to the job on a cold January Day. Told me to change to a riello.
I asked my plumber/bother-in-law and he said hogwash, don't worry about it. The 30yr tech was right, and my Brother-in-law was wrong, (he's a newbie with 15yrs, whippersnapper) Whenever the flue is cold, and whenever the outside air gets below 20 degrees that burner gives me a bang.

Anybody run into this? Is there a fix for this? Something about the pressure vs draft? I can't remember what the old guy said.
V8-4 burnham cold start
AFG Beckett with type F air tube combination burner.
What are the propper pre-purge and post-purge start times?
Old 10-21-06, 05:59 AM
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The cold air thing is a issue at startup on many burners, when the burner lights you will get an expansion of gasses that the flue pipe is too small to contain. If you were to remove the draft regulator you may find that the startup bang stops because the expansion has a place to go. You cannot run without the draft regulator, so now what you need to do is to drop the draft regulator down from its current position by installing an elbow pointing downward into the tee where the draft regulator is now, then install another ell into this elbow so that you can re-install the draft regulator in its correct horizontal position. This in essence is creating somthing similer to a water hammer arrestor in a domestic water system.

I also look up and V8 boilers do not use the F head, so someone installed the wrong burner configuration. Check with Burnham!
Old 10-21-06, 06:29 AM
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Burnham V-8

I too checked the Beckett OEM Guide & Hello is correct. Burnham does not use the "F" head on the V-8. On a 4 section they spec a V1-0.
The draft regulator configuration Hello refers to is sometimes called an "elephant trunk" & was commonly used on Blueray boilers.
Old 10-28-06, 03:19 PM
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I installed a Burnham V8-3 with a Beckett AFG and a tankless coil after removing a 1960's Crane gas boiler with a tankless coil and had the same bang at startup. It would pre-purge for 10 seconds then "BANG". At the same time, it would slam the draft regulator closed. A few days after I installed it, I had the service tech over to tune it up because it was running lousy from the factory. He got it up to 86 percent efficiency (from 60) but it still continued to bang on start-up, just not as bad. Just had to live with it. I did however go from using 1800 therms of natural gas per year ($2200) to only 600 gals of oil per year with the conversion. So the Burnham did do me well. I sold the house 6 months later and now I am staring at a 1957 American Standard Arcoliner. Probably will go with the Peerless WBV with a Riello when I'm ready.

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