Oil furnace tune up

I have an annual maintenance contract with Sound Oil, so they sent Ron out for a once-a-year tune-up. He taught me all about the system. It's a modern Armstrong furnace and it seems to be in good shape.

Ron replaced the nozzle, the part that meters the spray of oil into the burner. There was an old electronic filter that pre-dated the furnace. Now it's just a box with a paper filter in it--Ron replaced the 20x25x1 filter, and we found the "guts" of the electronic filter device behind the furnace box.

He replaced the oil filter (it's the lower cylinder in the photo). The glass cylinder is a "tiger loop" that eliminates the need for an oil line back to the top of the tank. An abandoned line is in the floor. The remaining oil line comes from the bottom of the tank.

He tested the efficiency with an electronic meter. The furnace label says 81%, and Ron measured 82%. The meter read absolutely 0 monocarbons in the exhaust and a net stack temperature of 375 (actually the meter said 420 or so, and Ron calculated the adjustment himself). 8.1% of the exhaust was O2.

He saw a little oil in the base of the chassis. He explained that a few drops come out of the nozzle after it's been shut off. They are designed to run into the firebox, but if the furnace isn't installed level, the oil runs the other way. Ron dusted the inside with "Odorgon" powder.

Ron showed me where the reset button is and explained that there's a lock-out mechanism if you press reset 3 times. They want to avoid "flooding" the burner with oil that's not being burned. There's also a safety switch if the blower shuts off and the furnace itself overheats. Ron tested it and it's working.

Ron put new Sound Oil stickers over the old ones--Sound Oil bought the old company. In fact, Ron found his initials on a service call from 1996.

Ron measured the oil in the tank. 18" in a 300-gallon tanks means I have about 140 gallons. I thought they had filled it, so I'm burning it at an incredible rate if so. He smeared a chemical on the dipstick that changes color if it touches water. If there is water in the tank, Ron explained, it sinks to the bottom. The very bottom of the dipstick turned red--a trace of water is not a problem.