Gas and Oil Home Heating Furnaces - Corroded oil burner nozzel problems

I am trying to track down a recurring problem. The oil nozzel keeps getting corroded with sludge, which shuts down the burner. What I am doing know is cleaning it or replacing it, but this is NOT solving the problem. Here is the history:

Had heater cleaned in summer
Lasted one month before clogging up.
Replaced nozzel, lasted two and a half months before clogging up.
Cleaned nozzel, lasted one and a half months before clogging up.
Replaced nozzel, lasted two weeks before clogging up.

Does anyone know what is causing this problem?

A repairman replaced the nozzel the first time, he said that:

1. The nozzel could be bad. This does not seem to be the problem
2. The arc could be weak. He checked it and he said it was fine
3. I could be getting dirty oil.
4. Arc tips out of alignment, he said they were okay

What I'm trying to do is systematically eliminate possibilities:

1. Nozzel
2. Piece of equipment that the nozzel connects to
3. Oil filter, did not replace yet until I get answer to my other ?
4. Dirty oil

There does not seem to be anything else that could go wrong, this heater seems pretty basic to operate.

As you can see the nozzle getting clogged is getting worse.

Can someone help me.

Thanks,

jrrepairman

My suggestions would be:

1) The oil filter should be changed frequently. Once a year is not a bad idea, filter cartridges are cheap and cost only a few dollars each.

2) Check (and clean if necessary) the filter screen at the pump.

3) Is it possible when the filter cartridge was changed that some debris entered the line between the filter and the pump?

With a new filter cartridge in place, it might be a good idea to flush the oil between the filter and the pump as well as between the pump and the nozzle.

4) Dirty oil is also possible.

Good Luck

TheZman

In addition to what theZman suggested, you need to be sure the electrode gap is correct and its position with the nozzle is correct, and of course the proper nozzle spray pattern. Also, if you don't have close to 100 lbs spray pressure, you will get fouled nozzles and poor combustion.

Thanks everybody,

First of all, I finally found the documentation for the oil burner; this is my mother’s burner. She’s 90 and sometimes can’t remember where she puts things.

Okay,

Zman, the filter was changed during the summer service; the burner was first used October 20 and failed to ignite on November 20. The problem has deteriorated since then

You mention flushing between the pump and nozzle. Can I just unhook the small length of tubing from the nozzle unit ( what is that thing called? ) and start the burner? This way the pump will just flush the oil into whatever container I use. Will the pump run long enough to flush the system before it shuts down or should I start it up a couple of times? Will starting it up without the oil running to the nozzle damage the nozzle or anything else?

Ahasbeen,

I have the specs for the electrodes now, but since I’m not anything near serviceman quality I’m plan to purchase a new electrode unit ( if that is what it’s called ) and then tinker with the old one.

What determines the 100 lbs of spray pressure? Is it the pump? Nozzle? Combination of both?

When the serviceman came to fix the burner the first time it shut down he said that a bad arc could also cause this problem, he checked the arc by holding a screwdriver between the poles and said it was fine.

If I do the above procedures then it would seem to me the only other possible problem is dirty oil or maybe a dirty tank, is this possible? Can the tank become corroded over the years and cause dirt from inside the tank to flow through the line; it seems to me that is what the filter is for. I didn’t change the filter yet, but when I get it out I plan to tear it apart and see if how dirty it is or if sludge is there.

Thanks again for everybody’s help.

jrrepairman

Unscrewing the small tubing from the "gun" is a good place to bleed the pump. You don't want to put raw oil into the burner pot. Operating the pump at this time won't hurt anything but you need to change the filter first b4 doing anything. As for adjusting the pressure, to be honest with you, I've forgotten exactly where on the pump the adjusting screw is. I think its a screw underneath a cap. Maybe one of the other guys out here can be more specific. In any event you will need a gauge. Theres a good chance the filter was so clogged up, it reduced the nozzle pressure. This is another reason you need a pressure gauge. Buying a new electrode assembly is ok if the old ones can't be set correctly, but setting them correctly above the nozzle is another matter and if you crack one of the porcelin electrodes, then all is for naught. I recognize you want to help out your mother, but if its not right and there's a problem with this oil furnace, your mom may not realize that there is a problem and believe me, an oil furnace can shake, rattle and roll ! And yes, you could get some trash from the tank but the down tube is well off the bottom and the filter should stop any trash from getting into the pump.

ahasbeen,

Thanks. So, if i replace the filter, bleed the line at the electrode assembly, and replace or check adjustments on the electrode assembly; that's about the best I can do on my own, right?

If this does not solve the problem then it's either:

1. Pressure at nozzle, which I may as well have the serviceman adjust since he knows what he's doing and already has the guage.

2. Dirty oil, which a clean filter should solve this problem anyway unless sludge gets into the line at filter replacement (which bleeding at electrodge assembly should fix).

Also, I have the documetation now as should be able to find where the pressure adjustment is on the pump IF I decide to dive in that far. I'll see what the local equipment warehouse has and what it costs, who knows; I may become a top notch oil burner man :D

Thanks everybody, I think I have the information I need to at least isolate the problem to a particular piece of equipment. At least this will save service charge time if I eliminate those things I can troubleshoot and repair myself.

Oh, by the way; this is really a nice forum. I found it just by hitting links trying to find information on my problem. I'm a real doityourselfer, luckily I haven't got in over my head yet and had to call in REAL professionals to bail me out. Probably because I research what I'm going to do BEFORE I do it (like my current problem); at least this way I have all my ducks in a row and know what I'm unscrewing and cutting before I do it.

jrrepairman

Hello jrrepairman,

Ahasbeen suggested some excellent ideas about pump pressure and electrode spacing. If these are off, you will get improper or incomplete combustion.

A simple test is to let the furnace warm-up for 1/2 hour and then go outside and take a look at the smoke from chimney.

It should be colorless (indicating complete combustion). White smoke is OK while the furnace is warming up and driving out the water vapor. Black smoke after warm-up indicates combustion problems. Similar rational applies to the exhaust from the muffler on automobiles.

A technician should check all the things ahasbeen mentioned as well as flue temperature, CO2 content in the exhaust gases as well as draft flap setting to diagnose combustion problems.

Good Luck

TheZman

I "THINK" I found the problem.

My brother was over mom's today and I was showing him the info I got from this site and also showed him what I was doing as far as cleaning the nozzle of debris.

Well, in the course of looking over the specs for the gun, nozzle, and electrode adjustment I noticed that the arc that is supposed to fire up the oil is HITTING the nozzle and NOT the spray.

According to the specs the two electrodes should extend past the nozzle one sixteenth of an inch, I guess that's so the arc hits the spray of oil to ignite it; well, it seems the arc is actually hitting the nozzle about one sixteenth of an inch BEHIND the head where the oil spray exits.

So, to me it looks like the arc is bouncing off the nozzle then hitting the oil spray to ignite it; it shouldn't be doing that, right?

I'm wondering if the serviceman put the wrong nozzle on or after putting the new nozzle on adjusted it on the gun wrong???????

I noticed that the piece which holds the nozzle can be screwed backwards or forwards to adjust the nozzle placement in respect to the two electrodes which arc the oil spray.

jrrepairman

Looks like you're on the right track with your problem but still to be determined is whether your serviceman put in the proper nozzle for that furnace. If its sized right, then the spray pattern (s) will work ok. Sometimes its hard to argue with "specs", but regardless of spray pattern, I would set the electrodes 1/2-9/16ths above and 1/8th inch in front of the nozzle. A smidgen more is better than a smidgen less. For your mom's sake, have a technician check out the flue temp, CO2 and any firebox leakage. Its money well spent!

Ahasbeen,

The burner is a Beckett AFG, the specs say 5/8 above and 1/16 in front; the 5/8 falls within your range and the other Beckett model says 1/8 in front, so you seem to be right on the money with the settings.

But I think I have a problem with the adjustments.

1. From the front of the nozzle to the burner opening is supposed to be 1 1/8 inches, if I screw the nozzle adjustment back won’t it widen the spray pattern; meaning, I’ll now end up approx. 1 ½ inches from the front of the nozzle to the burner opening. For some reason this doesn’t look good to me. Won’t the spray pattern splash off the edges of the opening if moved further away?

2. Next, there is a screw on the gun which when loosened allows you to adjust the electrodes; but if I move the electrodes forward the amount needed ( approx. 3/16 inch ) that would seem to place the rear of the electrodes to far forward from the springs which carry the original arc. I don’t know how to explain it, but a lid covers the gun that has two large spring type units attached to it. I remember when the serviceman tested the arc he held a screwdriver across these springs.

The other option is to manually raise and bend the electrodes forward to clear the front of the nozzle allowing the arc to strike the spray rather than the nozzle. I do not want to do this because they will surely break; also, it seems it would be rather difficult to get the electrodes perfectly in line by bending with fingers or pliers. For some reason I just don’t think this is a good option.

A final option, as I stated before, is purchase a new gun and see how that is adjusted at the nozzle head; but then I still have option one to contend with. I would still have to adjust the nozzle to be 1 1/8 inches from the burner opening. Probably putting me in the same situation I am now.
I just wish I knew what the original serviceman who came to clean the furnace in the summer did to cause this, it’s just to much of a coincidence that this would happen for the first time since she had the furnace (10 years).

I guess I’ll go with option two and see if the arc across the two springs will start the process in motion.

OKAY, here's an update. I lifted the lid with the springs on it and it appears the springs set down approx in the middle of the electrodes which means I have about 1 1/2 inches to play with. Can I assume that it doesn't matter WHERE the springs make contact with the electrodes, as long as they DO make contact with them?

Oh, just EXACTLY what is a serviceman supposed to do when doing the yearly service?

The people that come to my mother’s house:

Replace oil filter
Replace air filter
Replace nozzle
Clean ducts to chimney
Check chimney for proper flow
Vacuum dirt around motor

Should ‘t they also do this:

Check CO 2
Check flew temp
Check nozzle pressure
Make all proper adjustments

Both you and Zmann mentioned all this stuff but no one EVER did these things during the annual service call. For a hundred dollars I think the call deserves more than just two filters, a nozzle, and a quick vacuum of some dirt. I mean, the object is to get this furnace in TOP running condition so NO problems occur over the winter; if they don’t perform ALL the above functions how do they expect to accomplish that?

jrrepairman

jrrepairman, I believe you've come to that point in time for you to call your oil supplier and ask that they send out their top tech to tweak your furnace. If they can't, ask for a good recomendation or go thru the yellow pages. And when he comes out, try and rely on him to do whats right. Stand back and watch. Lets face it, you've already acknowledged that you can not do a complete tune-up and will have to get a tech out anyway. By the way- I'd dump the wannabe repairman that created the problem.

ahasbeen,

Very good advice, however :D being the doityourselfer I try to be I took the gun down to the place that serviced the furnace and he looked at it and agreed that the serviceman did indeed misaligne the electrodes. He realigned them now the furnace starts up purring like a finely tuned Farrari GT 350. He said that was the problem. I also purchased a new set of electrodes for six bucks because he said they seemed worn down a bit.

Anyway, I'll take the gun out in a week and check it for bujild up; but just by the way the furnaces purrrrred to a start I believe this is going to solve the problem.

Thanks alot for all your help, because of that I can now service the furnace myself as good as they were doing. As far as checking the CO 2, flue temp, and nozzle pressure; I can have a compatent service person do that for me, or maybe I'll invest in the guages and do that myself also.

Again, thanks for the help.

jrrepairman