Much more details are needed..
Where did you find the soot?
Name, model of furnace and the fuel.
You should have some co in the exhaust. When was your meter last calibrated and did you set it up in the fresh air outside before bringing it inside to measure the co.
Check the top of the heat exchanger via the plenum vent for signs of something melted or burned.
whatever the cause it is serious..call your insurance and call in a service pro to check everything out...may have been a delayed ignition causing excessive soot in heat exchanger and flue pipes to be blown out into the house...could have cracked heat exchanger that allowed soot via you supply air vents in which case it is life threatening!
Where is the soot the heaviest..check around furnace and flues and in and around supply air fan and ductwork...CALL INSURANCE have everything checked and cleaned professionally..if things can't be cleaned satisfactorily insurance should replace ..like furniture/clothing
Call insurance co. I had a fire place back up for just a few seconds, much less than half a minute. My daughter lite a fire using a wax fake log, actually two of them. the damper was open. a cold chimney with no draft. she smoked the house like you wouldn't believe. a two man cleaning crew was here for 2+ weeks. then I had to repaint the entire house.(really not finished painting and it has been 2 1/2 years) what a mess.
My brother in law had an incidence where the heat exchanger failed on an oil fired furnace. ins clean and paint. oil co replaced exchanger things ok for a while. happened again. upon inspection exchanger was installed wrong. start the process all over again. clean paint and ins co dropped them after the second time.
get the furnace inspected yesterday if not sooner !!!!
A forum community dedicated to Do it yourself-ers and home improvement enthusiasts. Come join the discussion about tools, projects, builds, styles, scales, reviews, accessories, classifieds, and more! Helping You to Do It Yourself!