Lennox Furnace Error Code E220

E220 indicates a hard lockout caused by an open rollout circuit. The flame rollout switch, a thermal safety device near the burner assembly, detected flames or hot gases escaping outside the combustion chamber and shut the furnace down. The furnace stores this fault and will not restart automatically, even if the switch has since cooled and closed on its own. A technician must identify the root cause and manually reset the unit before it will operate again.

No. The E220 lockout exists specifically to prevent unsafe furnace operation. Flame rollout is a serious condition that can ignite nearby components or introduce combustion gases into living spaces. The furnace has shut itself down as a protective measure, and it should not be forced back into operation until the cause of the rollout has been identified and corrected by a qualified technician.

The most common causes are restricted or blocked flue venting, a cracked or obstructed heat exchanger, and a failing inducer motor that cannot maintain adequate draft. Dirty or misaligned burners can also produce flame patterns that extend outside the combustion chamber. In less common cases, the rollout switch itself may have failed or developed a low trip point and requires replacement after other causes are ruled out.

You can perform a manual reset, but the E220 hard lockout is designed to prevent the furnace from restarting without intervention because the triggering condition is a potential fire hazard. If you reset the furnace without correcting the underlying cause, the rollout switch will likely trip again. In some cases, repeated resets without repair can damage components or create unsafe conditions. It is strongly recommended to have the cause diagnosed before resetting.

Repair costs vary widely depending on the root cause. Cleaning blocked burners or clearing a flue obstruction may cost anywhere from $75 to $200 in labor. Replacing a failed rollout switch typically ranges from $100 to $300 including parts and labor. A cracked heat exchanger is the most expensive scenario, with repairs or replacements potentially ranging from $500 to well over $1,500 depending on the severity and parts involved.