Gas and Oil Home Heating Furnaces - "Tobacco Stain" type residue in home

Hello. New here. Looking for some insight and answers...

I live in a 1950-something ranch-style home with a full basement. Our heating source is a 1950-something oil furnace (located in the basement). The furnace itself seems to work perfectly fine, and we are on a regular service/maintainence plan with our heating oil provider who services/cleans/repairs the furnace regularly.

My concern: When I use the humidifier or vaporizer in my kids' room on the main floor, or when the small main floor bathroom gets especially steamy, a tobacco-colored, golden brown liquid substance accumulates in the droplets of additional moisture that collect along the corner where the ceiling and wall meet, and then drip, or run down the wall. The substance is oderless and does not seem to be sticky, but is really nasty looking. I am very concerned that this is a substace that is released by the the heating system, collects in its dry (almost invisible) form on the ceiling and walls, but then is liquified and "rinsed" in to little pools with the added moisture. I am concerned that this is a possible harmful substance that my family is inhaling on a regular basis.

The filter on the furnace is changed regularly, but could this be the culprit? Is it just dirty and, therefore, not really cleaning the air emitted into the house? Help, please! I'm very concerned that my kids are unnecessarily breathing something very dangerous. Any advice or insight would be much appreciated!

I did not grow up with oil heating so this is all new to me. Thus, I'm a bit leery of it, and its safety.

Not sure why this thread was marked closed. If you have a hole in your heat exchanger inside the furnace, you will get more dirt than you should in the house. How harmful is not certain. Carbon monoxide isn't the real problem because properly adjusted oil furnaces don't give off a whole lot of CO. Do you use a pleated paper air filter? If not, I suggest you switch to one. You could also have someone inspect the supply duct system for dirt. Does anyone smoke in your house? Did the previous owners. Do you ever use a kerosene heater or know if one was ever used in the house? How about candles? Do you burn them? There are many sources for the type of stains you see but don't rule out other sources while you look for the problem.

Ken

Ken about covered it all.You could have the oil tech put a smoke bomb in the furnace just to make sure. But if its from the furnace it should be black.;) ED

it sounds like some form of carbon is forming...most likely due to someone burning candles. These days it's popular, or even incence. Is it on all 4 walls, one room or several? Does anyone smoke?, it may be nicotene. If not, maybe the previous tennants did.
Wash the affected wals with TSP (trisodium phosphate) Dirtex is a brand name of TSP. Painters use it before painting.

:p

Any recent plumbing work? I had a lady that called once when every time she showered the bathroom walls got a brown haze on them. Finally chased it down to 65 feet of new copper how water pipe and all the flux in the line.

Location of residue/stain in the rooms:
The residue/stain seems to accumulate heavily on the east wall/ceiling corner or each of the rooms where I"m having the problem (bathroom and kids room). There is a small ammount of accumulation on the north and south walls/ceiling corners, and virtually none on the west ceiling/wall corner. Does this seem wierd to anyone?

Location of heating vents in relation to the problem area:
Heating vents are just above the baseboards in each room.
In the bathroom, the vent is in the north-east corner of the room, just below where the problem is primarily occurring.
In the kids' room, the vent is completely on the opposite side of the room from where the accumulation is most heavy, and in this room, the vent is right next to a door in to a hallway.

Smoking:
I have no idea whether or not the previous owner was a smoker. I don't recall a smoke smell when we moved in, or lingering in closets or below cabinets. However, I'm sure that dosent really mean anything. No one in our family is a smoker. This is, as I mentioned, a tobacco-stain color, so this could well be the case if the previous owners were.

Candles:
I do occasionally burn a candle in the bathroom, but never in the kids' room. I actually did suspect the candle as the culprit when the problem began in the bathroom, but then when it began occurring in the kids' room..... hmmmmmm...
Again, I suppose the previous owers could have had candles in that room as well.

Thank you all for your suggestions. I really appreciate your input. I'll have the oil provider do a more through check of the furnace per you suggestions. Thanks!