soot filled&smoking every 2 weeks

hi I have a oil fired boiler that heats my house with hot water baseboard,it runs fine and cycles through running and shutting off normally,the problem is about every week and a half to two weeks it starts poring out smoke and the top of the burner fills with soot,so I disconnect the flue take apart top of boiler remove baffles and shop vac the whole boiler,the baffle holes and the flu then put it all back together,the problem is it keeps doing this every couple of weeks.
can any body tell me why this is happening and what I can do about this?
thanks dave

 

You need to get a pro in there to properly service the burner & boiler. There can be any number of reasons this is happening. Make sure the servicer performs a combustion analysis, preferably electronic, when he/she is finished. Most service people don't mind you watching & asking questions.

 

dave:

This condition is often caused by a chronic lack of combustion air.

A burner flame needs a large supply of air in addition to the high-tension spark & fuel to operate properly.

Did you recently add insulation to the boiler room, so there's no air getting in, or is the boiler in a confined space (in a closet, for example, or confined to a similarly small area)??

Even if the boiler room is relatively large, there has to be at least a 4" to 6" hole to the outside to let air in; if there isn't, the flame will burn rich & quickly clog up the combustion chamber with soot.

Also check to make sure there are not restrictions or soot buildup in the smoke stack piping, the chimney, & chimney cap (if used).

Aside from cleaning out the combustion chamber & heat exchanger, you have to make sure there is a clear path for exhaust fumes to go up & out the top of the chimney.

Always wear a dust mask; this stuff is rough on the lungs.

After cleaning everything & introducing more air into the boiler room, use a mirror at the base of the chimney to see if you can see daylight thru the chimney (do this during the day), if you can't, the chimney is obstructed & must be cleaned with brushes & extension rods.

With everything clean again, & the boiler fired up, leave the observation port open, use cigarette smoke or a smoldering piece of rope or cardboard to hold near the observation port;
the smoke should be sucked into the combustion chamber without hesitation.

Grady makes the point that if the flame adjustment controls/ combustion is off, you could still get a too-rich flame that you can't see by eyeball, that could still soot up the boiler eventually, & will waste expensive fuel; thus find a service person who can do a good instrument-based flame combustion adjustment.

 

thanks guys,I will clean it out adn clean it all up around the heater room and adjust the air shutters tommorrow morning and a a I'll let you kow how I make out
thanks dave

 

By air shutters I hope you are refering to some shutters external to the burner. Without some training or experience, please do not adjust the air on the burner. To do so can create a hazzardous condition worse than the soot & smoke.

 

Change the nozzle while you're at it ($2) & have 1 or 2 extras on hand; soot problems in the combustion chamber usually cooks the nozzle orifice, which will quickly soot up the boiler; the orifice facing will usually appear distorted.

Try doing the smoldering rope smoke test when the boiler is cold as well as hot; a chimney with a good draft will suck some test smoke into the combustion chamber & up the chimney even when cold.

You should also be able to reduce soot if you provide adequate supply air into the boiler room (leave a screened door or screened window open if you have to).

Better system draft on an operating boiler can be improved by cleaning the inside of the flue piping between the boiler and the chimney & checking for any blockages at the base of the chimney (a common area of soot buildup).

Also seal all seams & cracks of the flue pipes with high heat caulking compound or furnace cement (regular caulking compound can't be used).

If any soot coats the flue pipes & chimney, it will insulate the surfaces, preventing them from getting hot, so they can induce better draft.

Combustion exhaust gases must remain hot in the absence of any flue pipe seam cracks that would otherwise suck unwanted air into the flue pipe; sealing will keep the hot exhaust gases much lighter than air & will greatly increase exhaust gas movement up & out of the top of the chimney.

 

Another thing to check is if the fuel in the tank is dirty; if the tank hasn't been cleaned in recent years & especially if the fuel level is at the bottom of the barrel, the remaining fuel could be unuseable.

Remove a small sample of oil from the tank & hold it up to the light; it should have the appearance of a clear red wine; if it's not clear, it may be a major cause of your soot problem.

Unfortunately, the bottom of the tank is where dirt & water from condensation collect, & this is usually exactly where the fuel line sucks in its fuel to supply it to the oil burner.

Install a new line filter (preferably a Gar-ber) & clean or replace the fuel pump strainer inside the pump, sometimes this is enough to clear up the problem.

You can check if dirty/contaminated fuel is the problem by buying a clean gallon of kerosene or #2 fuel at a local gas station & temporarily rig up a 4' length of flexible copper tubing.

Disconnect the main fuel line & bend one end of the copper tubing & insert into the kerosene gallon jug,; modify a short steel or copper nipple so you can attach to the fuel pump housing & run the boiler for a week or so on the clean gallon of kerosene to see if that clears up the problem.

 

The heating supply stores & some big box stores carry an 8 oz bottle of "Hot" fuel oil treatment for ~$8; this is designed to keep the water condensate & sludge particles in suspension so they can be burned; this & other similar fuel additives are worth a try if the fuel oil tests dirty.

 

Without test equipment you're shooting in the dark hoping to fix a problem that you don't know the cause of. If you end up with a major puffback that dumps soot in the house, figure on 20 or 30 thousand in clean up costs.


Pete

 

Thank You Pete, that's the point I've been trying to make. The cure may be very simple but on the other hand, it may not. Since the boiler soots soon after cleaning, something else is causing the problem. Could be as simple as a dirty fuel system, could be any of a dozen or more other things. Troubleshooting an oil burner for soot problems is not something one can learn in a few minutes on the internet.

 

Yeah, do what Grady says. You will end up with less headaches in the long run if you just hire a tech who knows what s/hes doing. The other people responses are possible problems but a tech will be able to figure out the exact problem and fix it the first time, with the right adjustments.

 

thanks for the feedback,I cleaned it out again and replaced the nozzle and in line oil filter,if it soots up again I will have to get someone out here to see what the problem is,thanks again

 

I had the exact same problem during the winter months, the problem was a weak transformer. It took 4 service calls to get it right, thank god for service contracts.

 

4 times? Good thing for service contracts when you have a bad tech.