Trane Furnace Error Code ERR 22

ERR 22 is a soft lockout code indicating the furnace failed to establish or maintain a flame too many times during a single call for heat. The lockout triggers when 10 recycle events or 3 ignition attempt failures occur within one heating cycle. The furnace will lock out for one hour before automatically attempting to restart. The underlying ignition or flame sensing issue must be repaired to prevent the code from recurring.

ERR 22 itself is a protective response built into the furnace control board to prevent damage from repeated failed ignition cycles. The lockout is not a dangerous condition in the immediate sense, but leaving the underlying fault unrepaired means your home may not be heated reliably during cold weather. If you notice a strong smell of gas at any point, leave the home and contact your gas utility before attempting any diagnostics.

Repair costs depend on which component is faulty. Flame sensor cleaning is typically included in a standard diagnostic service call, which can range from $75 to $150. Replacing a flame sensor or igniter generally costs between $100 and $250 including parts and labor. A gas valve replacement is more involved and can range from $300 to $600 or more depending on the part and labor rates in your area.

Resetting the furnace by cycling the power or the thermostat may clear the lockout state temporarily, but since ERR 22 is a soft lockout it will also clear on its own after one hour. However, resetting without fixing the root cause means the furnace will almost certainly lock out again during the next heating cycle. A proper repair of the underlying ignition fault is required for a lasting fix.

The most common fix is cleaning or replacing the flame sensor, which is also the least expensive repair to start with. If the flame sensor is in good condition, the next steps are inspecting the igniter, verifying gas supply pressure, and checking the venting system for blockages. A qualified technician can use a multimeter to test the flame sensor microamp signal, igniter resistance, and gas valve operation to pinpoint the exact fault.