What is flame rollout an indication of?

Flame rollout is an indication of a dangerous form of back drafting. This phenomenon occurs when the combustion gases from a furnace or appliance do not adequately vent to the outside and instead flow back into the living space. This can happen due to obstructions in the flue, improper installation of the appliance, or insufficient air supply for combustion. When flame rollout occurs, flames can escape from the appliance, posing safety risks such as increased fire hazards and exposure to harmful gases like carbon monoxide. Addressing flame rollout is critical for maintaining safe operation and proper ventilation in heating systems.