Smoke in the house
When a fire is burning in the house, a good amount of smoke can be found in the basement room where the furnace and cleanout doors from below my firebox can be accessed. When the furnace starts up additional smoke is drawn into the heater and distributed throughout the house. I opened both access doors and cleaned excess ash hopeing to discover some type of pluggage and sealed around the openings to no avail. This problem just started. What happened ?