What is a puff back?
There are two reasons that puff backs occur. Improper ventilation is the most common. Ventilation can be restricted by foreign objects or when the barometric pressure drops outside and does not allow the exhausting air to flow freely. This forces the air back through the furnace, picking up soot and releasing it through the ventilation system. The other is caused by pinholes in the heat exchanger which allows the soot to be dispersed throughout your home. The steps needed for restoration are the same as in a contained fire and severe fire.
