More Crookedness...
I knew of a guy in my hometown who sold people "Energy saving nozzles" for their oil furnaces, now their are many brands of nozzles, but none are more efficient than others,he charged 25.00 for them...nozzles back in the 80s could be bought for around 2.50, in those days we charged 5.00 for them...Its very simple to diagnose a cracked heat exchanger, or a stopped up one, or simply low draft...Draft is checked by punching a small hole in the flue pipe, and inserting a draft gauge, then check the reading,if a cracked or stopped up heat exchanger is suspected, turn on the burner, then open the inspection door, if a there is a proper draft at the flue, their should be no back pressure at the inspection door, if there is..by this I mean heat and fumes coming out, then the heat exchanger needs cleaning out..to check for a crack, hold the inspection door open and wait for the blower to come on, if when it starts there is a sudden rush of heat and fumes at the inspection door, you know there is either a crack or a bad gasket ..these are things a homeowner can check himself and avoid being ripped off.