There are several ways you can clean an oil burner nozzle but first you will have to remove the nozzle from the actual oil burner itself. The nozzle is located inside the blast tube and can be removed easily if you know what you are doing. Once you have successfully removed the oil burner nozzle you can clean it if its not totally destroyed. There are many different brands of oil burners, some of the top brands are Beckett and Carlin oil burners and chances are that you have one of these brands on your boiler or water heater.
No matter what brand of oil burner you do have the good news is that you can clean the nozzle on all of them. It is always best just to replace the oil burner nozzle because they are actually only a few bucks and why should you go through all that work to clean the burner nozzle just to have it fail or clog up on you again. There off course is many reasons why you would want to clean the nozzle. For example if your oil burner is new but you had some junk in the oil tank and now you just want to clean the nozzle because you feel it is still brand new and could just use a cleaning rather then buying a new one. Well in fact it is still best to buy a new one anyhow. Just think your oil burner is worth thousands of dollars, is it really not worth spending under $10 not to just replace the nozzle? If your answer is yes and you still want to clean the nozzle then keep on reading.
The nozzle should have a screen on it that will be clogged and this is why its just best to get a new nozzle from the start because usually the screen and the complete nozzle will be all gunk ed up. If you really must save the nozzle read the next paragraph below. Once you have removed the oil burner nozzle from the oil burner gun you can get yourself a coffee can or some other type of metal container that you can put diesel or kerosene into. Now take that coffee can or metal bucket and fill it with a few inches of diesel fuel or kerosene and let it soak for a few minutes.
After the nozzle has soaked in the fuel for about 20 – 30 minutes you can remove the nozzle from the metal container and wipe it down with a rag. You might also want to blow the nozzle of with a bit of compressed air so you can remove any loose debris if there is any left. Once you have let the nozzle soak you will want to remove the small sintered filter in the end of the nozzle and then remove the brass screw pin to be able to make sure that the steel orifice disk is not clogged up as well. If everything now looks clean and OK you can re-install the nozzle. If you go though this whole process of cleaning the oil burner nozzle and you still have the same results chances are that the oil burner nozzle will simply have to be replaced because it is just to junked up with debris.