OIL FURNACE HELP
This furnace gets its fresh air from the bottom side of the furnace. I do have a whole in the wall of the garage a size of a 5 gal. bucket & the bucket is what i used in the whole. I cut the bottom out of the bucket stuck it through the whole & put it up against the furnace where it gets its fresh air. On the outside of the garage i nailed screen so nothing could get in.
OK but is it sealed in it's own space? Sounds like "not." Also stuff like the exhaust fan may be reducing the draft--you HAVE to understand pressure. When you have a combustion appliance in a space, and an exhaust fan, depending of course on how large, the fan depressurizes the room, AKA causes a low pressure area. I've seen buildings with SEVERE exhaust fan (or commercial range hood) problems where the building is actually under a VACUUM. This will reduce the burner draft to zero or negative, ---and the burner will attempt to "draft" right back out the burner inlet
Also, forgetting that part completely, an oil burner that has problems, wrong/ dirty nozzle, wrong fuel pressure, and adjustments, or even just run "too cold" --such as starting in a cold space and never fully warming--can cause the heat exchanger and stack to soot up and THAT will reduce the draft.
There is only one way to properly tune a pressure burner, and that is with instrumentation. And knowledge. You need at minimum, a draft gauge and stack thermometer, and some sort of combustion analyzer to measure CO2. You need a pressure gauge for the burner and be able to clean and replace the in-burner filter if there is one, adjust the electrodes and so on
And you have to have the knowledge to recognize various burner problems.
I haven't touched a gun burner since the mid 90's and If I could not adjust it in one try, simply, AKA if it seemed "not right" I would call a current qualified burner man. And I used to maintain them.
