Need advice on new burner

Mike E_2

Thanks for your replys so far. To answer a few questions.

It is a F100-50HE. AFII-150. It has the HLX-9 head. A few weeks ago I bought the 6 slot head, but just after it came, I read a statement on Beckett's web site saying how they made a few changes to the head assembly on the AFII in 1995. So the new 6 slot head I got doesn't work.

The nameplate on the boiler says 1.40 gph, however, it was delivered and originally set up with the 1.25 (1.5 equiv. along with the #5 set screw - which is correct for 1.25, but not when you take in account the 140psi.)

J.C.A. - I don't know what the excess air and CO readings are because I am just using a wet kit right now. I do plan on buying a Bacharach Tech 60 within the next few weeks.
The stack temp with the 1.25 nozzle is 410F. The .85 was only used for a couple of days and hasn't been back in since.
I don't have a sytem bypass, however my return temps are always above 150F, except for about a minute when a zone first opens. (180 HL w/ 20 diff)


I do plan on having a condensing gas boiler installed during the summer - would love to get a GB142, but don't think I can swing that. It will probably be a Munchkin. I already have gas service for my pool heater, but it'll have to be run into the house. I will keep the oil equipment working as a back up, and in case oil prices become cheaper than gas in my area again. Right now oil is 2.25/gal, and gas is 1.28/therm.


What makes a Vaillant so difficult to fire? Isn't it basically the same as any other 3-pass boiler casting such as Buderus or the MPO? But why are those two so much easier to fire then?

Mike E_2

Need advice on new burner

I have a Vaillant F100 3-pass boiler from the early 90's. It uses basement air(plently of make up air available), and vents into a 2-story chimney. It has a Beckett AFII burner with a 1.25 nozzle @140psi (1.5gph). It has always been quite difficult to get set up burning cleanly. And now the absolute best I can do is slightly higher than a #1 smoke(slight hint of reddish orange too) along with 10% CO2.

Also, 1.5 gph is now oversized since I no longer use this boiler to heat my garage, and I have done some insulation/weather sealing work around the house. I have tried to downfire slighly with a 1.0 nozzle (1.2gph) and .85 nozzle (1.0gph) both times using the proper set screw, but both of these have not worked at all. The .85 has a very strange sweet smell, and builds up an orange varnish in the stack pipe and on the sight glass that can only be removed with acetone and a razor. The 1.0 was puffing alot, would loose retention, and was very smokey.


So, I'd like to get rid of the AFII and put a new burner on that will be easier to work on, and run cleaner. Any recommendations on a burner that works well with a high static pressure 3-pass boiler? I've read that the Beckett NX would probably be good, but is it still just OEM, or is it available as a replacement unit?

Thanks for any help,

Michael

John@Reliable_10

Well it depends on ..........................

if you have the F100-HE50 I would try this first. 1.10 60 B nozzle @ 140psi. Also this assumes you have ATII 150 with AF2-6 head stop screw #6. This boiler/ burner set-up was always harder than most to setup. You must set this up with a test kit. I would suggest finding a real pro to do this for you.P.S. there is a reason why this boiler is no longer available in the U.S.

J.C.A._3

10%CO2,

What are the excess air and O2 numbers ? I bet the CO is quite high ....

I would suggest keeping the boiler fired at minimum 85% full firing rate for starters. Any lower than that and all kinds of strange things start to happen....and most of them aren't good! The redish buildup in the flue piping is CONDENSATE! You will be replacing that piping real soon if'n you don't get some more fire in that puppy! Minimum flue temps at the breech should be higher than 325° net IMHO, and with that tiny fire, you aren't going to get it.

Is there a system/boiler by-pass installed? This MAY help a bit, if the fire is a bit bigger.

My advice would be to save yourself some money and get a properly sized boiler in there now. (think it's going to be cheaper anytime soon?) If that isn't in the budget, my advice for a replacement burner (and I highly recommend THAT!) would be either a Riello or CCT EZ-1....fired appropriately. The Beckett AFG has come a long way since the AF2 was introduced, and may well work too, but I would go with the forementiond chioces. Personal opinion. Chris

Joe Grosso

Vaillant

Yes, a difficult boiler to fire. I would use Riello or Carlin EZ only. If using the Riello, use a long air tube(10") - runs better that way.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Eric L._2

How much more efficient

are those burners as compared to a 7 year old burner without the bells and whistles? What is it that makes them more efficient?
Thanks

Eric