We experienced damage from oil burner soot that backed up into the house. We're told the problem has now been fixed, by replacing the fire chamber and the installation of a negative pressure cutoff switch. We do have CO detectors, and they have never signaled a problem. There is still oil soot in the crawlspace and on the walls of the house. Is the oil soot in the crawlspace in danger of spreading back up into the house this winter, or will it stay adhered to the wood surfaces in the crawlspace? The system circulates the heat via hot water, so there are no vents to clean, but the soot came up through any hole it could find in the floor and through the electrical outlets. Cleaning the crawlspace would be a huge job, but I'd like to know before repainting the interior. I'll ask the painters: Is there any hope that a good primer is all that I'll need before painting?