Beckett AF Air Shutter

ww

I cleaned a Delco DB4 boiler and vacuumed before setting draft and doing smoke test. This has 1.25 80 degree hollow nozzle. I got draft over breech was just about 4 and little more and over fire just about 3. The smoke test when bringing the pointer to maximum side air openings at the 10 and final smoke reading of 6.

Played around with opening the main shutter and got the smoke down to just about 2 with pointer at 10. Of course I want a 0 smoke reading but turned it off and will continue tomorrow. I can't help figuring there is too much air in there and checked out the draft again and it was ok. I never had to open up the main shutter in other units. Any suggestions on this?

Steamhead

What were the combustion test results (CO2, CO, stack temp etc)?

What is your pump pressure?

Is the flame hitting the firebox anywhere?

EdTheHeaterMan

The Delco Boiler is over 40 years old, Correct? The Beckett burner is not the original oil burner for that boiler. There are no specifications that are/were published on this combination. This is where you need to have the assistance of an experienced oil burner technician. I know that they are hard to find, but someone is not getting this system set up correctly for you. I see you experienced the same issue last year here :

https://forum.heatinghelp.com/discussion/198866/hot-water-beckett-af-nozzle-and-ignitors-covered-in-heavy-soot

EdTheHeaterMan

Getting the proper air shutter and air band settings may not be possible on the burner based on the air tube combination. If your burner has the F3 fixed head on the end of the air tube, then you will never get enough air thru the F3 head. That head is rated for .75 to 1.25 GPH. If you have a 1.25 GPH nozzle and the pump pressure is set over 100 PSI, than you are over-firing that burner. Try a smaller nozzle GPH nozzle. Also try using a 70° A or 70° B nozzle and see what that brings you to.

HydronicMike

Your draft is too high over the fire. Make sure blower wheel is clean and transformer is sealed to burner housing, as well as inspection door is sealed.

What are you firing into? May be underfired.

ww

I fixed that problem regarding the soot and was caused by air tube being too far in. The temp at the stack was 710 and not yet subtracted ambient temp and know this is a high temp and was due to too much air when checked.

The burner has an F3 head. I am going to do a combustion test but ran into a roadblock adding some fyrite fluid to unit and looking for some fluid. Last night I was looking at gauges online and will take the pump pressure when i get gauge.

Have been looking and see they are so small like and inch and a half which is small so may have to get that one. I'll try a different nozzle. As far as flame hitting any part of chamber it's not easy to see that except for small hole on side. I did rebuild the chamber so that's ok.

I was thinking that this boiler probably had one of those old oil burners with a much slower rpm and setup as well. Other than these issues heats up well and doesn't use alot of oil either. With the help of EdtheHeaterMan was able to change this unit into a cold start boiler and bypass the coil. I put in a hot water heater which works fine.

ww

The chamber cover is 16 inch in diameter and the depth is 16 inches to the back wall.. There are three ribs or water jackets on floor. The back wall and the floor is made up with the wet blanket from Lynn. I know they always say 2 over fire and 4 over breech but moving around the door weight gives the same results plus or minus. A good idea is that gasket on the transformer and I did actually notice there may be some missing…so this could really have an effect on the air and draft as you mention Mike. The cover held on with 4 studs and nuts is sealed with a special rope from Lynn. I'll have to look for this transformer gasket which I've seen before in kits. Thanks

HydronicMike

You really need an electronic combustion analyzer to go along with your smoke gun to do a proper combustion analysis.

The wet kit isn't going to tell you CO, or excess air.

ww

Yes..I agree…was told Bacharach Intech and Testo were good…looked on Ebay..alot had bad O2 Sensors…and they cost alot new…so will look at that. This chamber in the boiler was a firebox that was removed due to being collapsed and replaced with a wet blanket on floor and target wall…so is bigger than original. I've replaced these things before with quickie type boxes but this boiler has a cover held on by bolts so to line up with the hole in box would be a challenge…other ones I've done had a top door to be able to line up the head to the proper depth. Maybe I have to get something else.

ww

Mike was thinking about what am I firing into…As I mentioned above when the front housing is off the diameter is 16 inches and the distance to the back wall is 16 inches. If i used one of those quickie 100's it would bring the chamber to a much smaller size. Using the wet blanket on the floor and the back wall makes the chamber really alot larger than original size with the firebricks. When figuring the chamber size I don't know where the sides would end on a set up like this…maybe measured at the intersection of the front to back wall at the nozzle angle. I'll have to see about this too. I see alot of these type of chambers online fixing the same way but who knows what problems they have. I spun the wheel and it looked clean as well..Just how much would that gasket change the numbers…I will be looking later at to where I can get that..I used to be able to just get nozzles and stuff easily but not many carry these parts anymore.

ww

One more thing Mike…you mentioned it might be underfired..maybe this wide expanse in the chamber set up like this and how it would compare to one of these inserts could be how being underfired now could be explained?

EBEBRATT-Ed

If you stack temp is 700 and it heats well you not underfired but maybe you should be. Or Baffle the boiler to get the stack temp down.

ww

ok..will try smaller nozzle..thanks

HydronicMike

https://forum.heatinghelp.com/discussion/comment/1850161#Comment_1850161

You would also have high stack temp from high draft and high excess air. Needing large amounts of excess air trying to get a clean flame is a pretty good sign of being underfired, or using the wrong head.