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44 FEBRUARY 2016 | FUEL OIL NEWS | www.fueloilnews.com HVAC/ HYDRONICS T his is from our book, Advanced Residential Oilburners, Figure 1, and addresses a problem that it seems the oil service business will have to learn to live with, like it or not, the oookies. Will they ever end? This article is about the oookies, a subject that has grown near and dear to those of you who make their living turning the screwdriver and keeping the home fires of oilheat burning, yep, my people, the service technicians. It is the week before Christmas, 2015, and we may be headed towards another winter that wasn't. It seems that after two tough winters we have already forgotten what a warm winter can do to equipment. First, I am going to go out on a limb, (so where else would you expect to find me), and blow up a few bridges (yeah, so what else is new). The subject is a phenomenon now called the "cold-soaks" or "running saturations," and for some others simply "the oookies." Now for those of you who are weak-at-heart—bail out now. This is where the excrement meets the blower wheel. There are two smells that technicians have come to know and dread. The first is when a customer has cherryed or dry-fired a cast iron boiler. It is like no other smell in the world, right? Even when you go to a cast-iron foundry you expect to smell that smell but nope, it's different. The other smell is from a particular type of plugged boiler. Not an average plugged boiler, but a particular type of plugging. Let me give you a description of this won- derful scene and cause some of you a daymare, Figure 2. First, the boiler is plugged from the bottom of the unit to maybe the top of the chimney. The soot in the base of the unit is soft and fluffy and as you work your way up the soot gets harder and crustier. The soot in the chamber area may be what appears to be oil- soaked and one of the dumbest things ever said by any of us is, "Thank God it didn't light off." Now, why is this statement dumb? Because it was running when it went off. Yep, when the cad-cell finally shut it off it was still running. Ever try to light some of this oil-soaked (?) soot? You need a torch! That's because fuel oil is 85% carbon and 15% hydrogen, remember your basic oilheat theory? And so, my friends, the hydrogen has been burned off and now you are stuck with something that is basically liquid carbon and why they call it cold-soaked. The hydrogen and ignition factor is gone, done an Elvis and left the building, checked out of the Hotel California, finite and poof! Some other things we do know about a typical cold- soaked unit are: 1. They happen predominately on wet-base boilers, steel or cast-iron. 2. They happen mostly to non-chambered units. 3. They happen on cold-start boilers providing domestic hot water. Not a good idea anymore and probably never was. We have discussed this before in previous articles. 4. They happen mostly on burners with intermittent (constant) ignition that have three-wire primary controls. Burners with interrupted ignition are not immune, but it does seem to help, a lot. 5. This situation did start occurring before red-dyed fuel and biofuels. So, those theories don't hold, but I am not ruling out that they may not have an effect, and I still question what these modern fuels are doing to the servicing of oilburners. 6. No brand of burner is exempt. 7. No brand of boiler is exempt. 8. Nobody really, really knows why this is happening, really? So, what do we do? Well, let's look at some more facts. 1. Cad-cells should only see direct light and the tubes of burners should never be painted silver, white or any other color than black or other dark paints. The stupid practice of painting tubes allows stray, indirect light to travel back to the "eye" and causes and allows the unit to go to a higher degree of pluggedness. People who do this are extremely dangerous. 2. Fact! You must maintain an ignition point for fuel oil to burn cleanly, hot and safely. Below that you are making smoke, period. This fact is not open for debate— it's physics, I don't know physics but I know oil burners. 3. When you open your inspection or swing-door or remove the burner mounting plate, you will find a perfect hole within the soot in the combustion area. That hole in the soot is caused by the high static fan and air handling parts that make up your high velocity retention head oil burner, and that's good! At least that was trying to keep the burner running right up to the very last second. 4. Draft (airflow) is the most important factor in the combus- tion process. The problem is that as boilers are becoming tighter, to become more efficient, draft is reduced through pressure drop and temperature. Always remember this golden rule about draft. Cut or lower the stack temperature by 50%, and you lower the thermal draft output by 50%. Okay, so many of us claim we really don't know what's happen- ing out there, but let's look at what some of my friends have done The Oookies! BY GEORGE LANTHIER Figure 1 Figure 2