I purchased a name-brand oil furnace two years ago. It replaced a workhorse 48 year old furnace which rarely needed attention, mainly the yearly maintenance. During these two years of using the new furnace, I have noticed a build-up of white and black particles on the furnace ledge, the burner box, and the floor. The techs from the heating co. have come out repeatedly. A setting was adjusted and a year later returned to its normal setting. A year ago I was advised to buy a new chimney liner which I did. The flue pipe has been replaced several times. When it was replaced in September, I could see it filled with "crud." It had previously been replaced 9 mos. earlier. It was replaced again a few weeks ago. Most recently two furnace techs told me that what I am seeing is "normal." They called it "condensation." (I thought condensation was water. These particles are similar to salt and pepper.) I have been continuously vacuuming the particles. The problem has been on-going for two years.

The most recent advice given to me was to just make sure I have the furnace cleaned every year (Yep-been doing that for years) and to "give it time."

Could anyone explain if this is indeed "normal?" To me it is not normal. Any insights would be appreciated. Thank you very much.