[jond65]

I have an ICP furnace with a Becket AFG burner. Last year on a few occasions I had to wipe the cad photo cell clean to get the burner running again. It was the end of the season and I figure it just needed a cleaning.

This season I am now getting an oil smell with the burner runs then blows the hot air from the vents. I did a bunch of research and spoke to a family member who works on oil burners, to far away to visit, and did the following:
1. Inspect the combustion chamber/fire pot, it is in healthy shape. So don't think I have a cracked heat exchanger
2. Pulled the beckett and the exaust flange and cleaned them, found some loose scale but not in the fire pot.
3. Replaced the heat shield in front of the nozzle, was bent and cracked
4. Replace the nozzle.

Before all of this my service guy replaced the oil filter, etc. However he did tape off and close the exaust damper. My family member told me NOT to leave it that way so I removed the tape and it is working as it should.

Now this is all done I still get an oil smell, but not as bad. I don't know if the photocell will film up with old again, should know within a day.

Where the photo cell reside it had a layer of soot and/or thin layer of oil, not bad. I cleaned it out. Also there was soot on the nozzle and parts around it and the old tube had some oil on it as well. I don't see any leaks that I can tell in the oil feed.

Bottom line is I think the system is running to rich and does not have proper oil/oxygen mix but would love to hear if anyone else has had this problem and know of a solution. Sorry for the long post.

[whburling]

I am not an oil boiler or furnace repairman.


The only experience I have is fixing my own boiler over the course of 20 years.

I would say you are thinking in the correct direction - the air fuel ratio is not correct. It is hard to evaluate that ratio without various instruments, but you can purchase a smoke tester without harming, too much, your home budget. While it does not inform you of the correct ratio of fuel to air, it does
Indicate the amount of soot your fire is producing. This measurement is valuable as a film of soot greatly reduces heat transfer from hot exhaust gases to heat exchanger and hence efficiency. Maybe is is more important (or just as important) as the co or co2 readings which is measuring the efficiency of the flame burn.

Another poor man's way to check your fire is to vary the amount of air going into the burner while concurrently watching the fire through a view port which is usually on all boilers or furnaces. You should be able to vary the color of the fflame from dark orange (alot of soot) to almost white (no soot).

A white flame has the least soot. A reason people do not run with an almost white flame is that one tends to have excess air at that point. Excess air means that the fuel has used up all the oxygen in the air that it can, and any remaining oxygen can't be used. Thus the fire heats up the excess air (which includes 20% oxygen) and pushes it out the chimney. You are thus throwing away energy at that point. I usually adjust the air to get a white flame and then back off just a bit toward yellow (not far enough to get orange, though).

To adjust the air, there are two adjustments. One is called the shutter and the other is called the band. Usually the band is set to a low number (there are numbers on the casting on the burner) and the shutter is set to a higher number.
The band fits around the circumference of the fan shroud... and the shutter is on one edge of the shroud.

To give you some idea for numbers. For a nozzle with a 0.65 gph rating, I set the fuel pressure for 130 psi and the band at one and the shutter at 2.5 to 3.. .


Build yourself a pressure gauge that fits on the output of the pump. Ask a supply house to give you an elbow, short pieces of pipe and a brass fitting to connect to the pigtail from the pump. It should not cost more than 20.00 and is well worth it.

Feel free to contact me if you have problems. As I mentioned before I am definitely NOT an expert. I am merely a guy who is doing his best to keep his boiler working as well as he can. I do appreciate the skill set of a repairman, but I just can not afford one at this time in my life.

whburling @ earthlink.net