Our house has a 32-year-old oil-fired warm air system. The furnace is "Armstrong by Magic Chef", and the burner is a Beckett Model "A". There is no central air conditioning installed. When the furnace starts, there is a smell of diesel exhaust, and over time there is an accumulation of particulate matter (coarser than soot) below the barometric damper. We keep the furnace well maintained, but the maintainer/oil supplier doesn't seem to be able to fix this (nor do they seem particularly concerned). The barometric damper is about 2 feet from the outlet of the furnace, and from there the chimney connector runs horizontally for about 10 more feet before entering the chimney. (Actually, the connector slopes down about 3 inches in the first 3 feet, and then slopes up about 6 inches over the next 9 feet.) I don't know whether the maintainer has done the necessary pressure tests at various points to make sure the BD weights are set correctly, etc. This particular damper is original, creaky, and leaky. (I would expect a damper to be more of a valve, so it is completely sealed when closed. This one certainly is not sealed when closed.) Are there any obvious things I should check or replace, or have the maintainer look at? I'm tempted to attach an auto air filter to the BD to at least catch the particulate pollution. Replacing the entire system is an option, albeit a last ditch one. If I did that, I would go for a sealed system with fan-forced air coming into the burner.

Hi all, I'm hoping someone can help me with this: I have a Bryant (Plus 90) 350MAV furnace and I recently noticed it seemed to be short cycling. Upon closer inspection I've found that it is actually the blower turning on and off after the burner shuts off. Sometimes the blower will start and then cut off instantly, sometimes it will run from a few seconds to about a minute. It repeats this for a while, followed by a few minutes of silence before it does it again a few times randomly. The blower seems to run fine / steadily while the burner's on, however. I've turned shut off the power to the furnace and turned it on again, get a 12 error code, and then the LED stays a solid red with no other flashes. Does anyone know what could be causing this? I've done some research but have yet to come across anything that close enough to try. The closest I can get to a possible cause seems to be maybe a faulty blower relay. A lot of similar sounding cases had different fixes so I'm not completely certain. Thanks in advance, I really hope someone here can tell me what's causing this. Will provide more info if needed.