Rough start

stevebar

My Beckett burner sometimes starts with a rumble and a puff of smoke back through the barometric damper.

The tech tuned it, but the problem persists. I suspect that oil is leaking through the nozzle after the burner shuts off and that this fuel accumulates in the chamber, and when it catches fire causes the rumble and smoke. I mentioned this to the tech, but he didn't have anything to say about it, but just commented that the draft was fairly high and recommended that I keep the door to the basement closed.

What makes me suspect leakage, and that I told the tech about, is that once after turning off power to the boiler before going on vacation for a few weeks (to save on fuel) the boiler restarted with a very loud rumble and clouds of black smoke. Thinking that leakage might be the problem, another time I tried shutting off the oil at the tank as well as shutting off power. When I did this the boiler restarted smoothly. Also, a sludge of black oil seems to fairly quickly build up on the lower side of the nozzle face.

Could leakage be the issue? Would it help the tech if I gather more info, such as if the problem is worse when there are longer periods between firing or other conditions..? Whether or not leakage is the problem, what explanations and/or solutions should I expect from the tech? I don't want to be a nuisance, but the tech didn't solve the problem with a tuneup.

icesailor

My experience: (FWIW)

The black crud on the nozzle is a symptom of not having sufficient oil filtration with spin-on oil filters. Two work best. It is also a sign that the nozzle strainer is becoming fouled and you aren't getting proper pressure at the nozzle outlet/orifice.

Open/lift up the transformer and remove the nozzle assembly. Shine a flashlight down the tube. Look at the end cone. In the hole in the middle, where the nozzle sprays through, do you see any black deposits around the edges? Stick your paw down inside and run your index finger around the hole, reaching INSIDE (outside) the end cone. You feel roughness? Take a old copper fitting brush with a wire handle and scrape the hard black carbon off. Rub it ALL off if you can. You must.

Replace the nozzle. Be sure that it is a Delavan 80 degree "H" or "B". It must be a Delavan 80 degree nozzle. If not, get another tech. Put it back together. Have proper filtration installed.

If you are not savvy, don't do this, but the pump strainer needs to be changed. If it is covered in black sludge, you do not have a spin on filter, but an antique oil filter that was designed during the Pleistocene era. Replace it with something that filters well.

Almost 100% of all Becket AFG's I found doing what you described, had carbon deposits built up on the end cones. The ignition spark would short out on the carbon going to ground, until it burned the carbon off.

They use carbon in automotive ignition wires.

My experience.

The other problem with sludge fouled strainers is that it holds the pump pressure for a moment while product flows out of the plugged nozzle, giving you "Afterdrip" which adds to the black scum on the bottom of the nozzle. And poor draft will drive AFG's to give up. Especially if the draft is positive when they go to start. If you connect a Mitco Qwik Chek Pump Tester between the pump outlet and the nozzle line, you should be getting a minimum of 100# PSI when running. When you shut it off, it should drop almost instantly to zero. If it doesn't, it is either a bad pump shut-off valve, or a plugged nozzle. If you replace the nozzle strainer with a new one, and the pressure drops to zero quicker than when you had the old one in, the strainer was/is fouling. If not, the pump has "Issues".

If he didn't put gauges on the burner, he wasn't doing his job. Ever see a AC tech NOT put their gauges on a AC compressor?

What brand & model boiler is this Beckett firing into?

SS,DD.
IMO.

billtwocase

Is the black spot on the nozzle where the electrodes are? What boiler do you have? Any fuel solenoid, or Clean-cut pump? Excessive draft, close the door? I would start with a new tech to begin with. There could very well be a bad check in your fuel pump. This is a fine example why here in Mass they made it code many years ago to have a DOV. I have seen the pumps fail this way before. Ignition, correct nozzle, and all other adjustments are also critical. Post pics, boiler brand, model, size, and what brand of nozzle, degree angle, and spray pattern, so we can tell what should be in your boiler.

stevebar

Thanks for your suggestions. You've given me a lot to ask the tech about.

I removed the nozzle assembly and photographed it and the cone into the chamber. As you can see in the photo, there was carbon buildup on the cone. I was able to get it very clean. When the tech did the annual maintenance he rubbed a brush around the cone, but he did not look to see if it was clean afterwards.

The nozzle was new a month ago ago at the time of the annual maintenance. The black buildup is heavier and more uniformly distributed than I have seen in the past.

I don't think there's a DOV on the burner (see photo), but I'm not an oil tech, just a homeowner who is interested in how things work, and a long-time visitor to Heatinghelp.com.

The tech who did the tuneup remarked that the draft is very strong and he recommended that we keep the basement door closed. I've been doing that since, but the fact is the burner has worked well for years with and without the door being open. Something is different now.The rough starting is new.

It's a Burnham V-33 boiler with a Beckett Model AF burner i. I seem to recall that years ago I looked into the boiler/ burner combination and it wasn't listed. Even so, it has given smooth, reliable service for many years until now. This may be our last winter on oil, so I do not want to have to make major changes right now.

I'd be tempted to change techs, but we have a service contract and I want to have the oil company get it right if they can. I was a little disappointed with the last tech they sent out when he adjusted the air by eye not long after another tech had used instruments to tune it. I am a believer in the scientific approach I read about in Heatinghelp.com

STEVEusaPA

Starting with the 3rd pic, someone moved the nozzle assembly forward. This decreases the air mixture and is part of the reason for the crud buildup. The 'Z' dimension is important and needs to be reset.
Pic 2. The electrodes are set wrong. Your suffering from lack of air, lack of draft-building up excessive heat at the combustion head. This is causing the effect with the oil drip. I would also make sure someone cleans the burner motor blower wheel.
Pic one is the result. The crusties on the head being the sum of all these problems
Edit: there's water in your oil

icesailor

There's no filter at the burner. If you do NOT have a Spin-On filter at the tank, and it is a General or a Ful-Flo, it is passing fine crud that is restricting fuel through the nozzle strainer. Replacing the nozzle won't solve it for long. Have a Garber spin-on filter installed at the burner and change the pump strainer and nozzle after the change.

Excessive draft? Did he consider adding a second RC to the stack?

Beckett's don't take kindly to excessively high draft. IME.

To my experience, when I see that carbon on the end cone, it will be misfiring and not starting. You have to get every bit of the carbon off.

billtwocase

I think the "Z" dimension looks close, but needs to be set with a gauge. How many more decades do they want to get out of those electrodes? Constant ignition, they should be changed yearly. The tips are burnt, and not adjusted right. The carbon on the endcone, and it looks like an F-6 which is good for that hollow nozzle you have in it, is telling me low pump pressure, and maybe a use a gauge to check the "Z" dimension setting. This was an old American Standard boiler before Burnham bought it out. The Beckett was put on at some point, probably late 70's. Those boilers came with ABC Sunray, Wayne originally. As others said, filtration, strainer replaced, check oil supply line, check transformer, replace and properly set them, set the burner up with analyzer, set draft over fire to -.01 to -.02 tops. There is no delayed oil valve on there, and those pump checks will open about 85 PSI, giving a lousy start in most cases. I would run a ,85 80 A nozzle, 140 PSI, and adjust from there. A 2 year old can work on these. That is sad. Post some more pics of the boiler, smoke pipe, chimney, etc

icesailor

Another graphic example of why adjustable head burners rule.

How long did it take him to remove that burner without making a mess? To check that illustrious "Z" dimension which everyone claims to check but I'll bet that few do. Especially when you are expected to "Thoroughly" clean, adjust and combustion test every boiler/burner in one hour. Expected to do 8 boiler/burners in a 8 hour day. I'll bet that he doesn't know what a Beckett gauge looks like or how to use one.

And if it came with a F12 head, and was down fired so that it needed a F6 head, unless it is a very experienced tech, they wouldn't know the difference. Nor have one in the truck. Or would the Service Manager allow them the time to fix it.

Time for a gas replacement.