smell boiler exhaust
I live in a converted garage apartment, on the second floor. The boiler is on the first floor. The chimney is on the roof not too far from a window that I sit near most of the time. (It's a small apartment.) When the windows are open, from spring to fall, I smell the furnace exhaust sometimes. When I first moved in I thought the smell was from passing buses. I have since figured out that it is the boiler. With the latest tune-ups in the past two years, the smell is better than before; it isn't as rank.
My question is, is this chimney faulty or just poorly placed? It extends about 3 or 4 feet above the roof. The boiler only runs for heat, hot water and occasionally on it's own, I guess to keep whatever water is close-by warm. There is no water tank. It heats on demand but is an old unit, probably 20+ years old.
It burns oil.
Any info and advice would be welcome. Thank you.