Lennox Error Code 311

Priority condition: Information Only-Dealer The heat firing rate has been reduced to match available airflow (cutback mode). This is a alert code. Furnace blower in cutback mode due to restricted airflow. • Reduce firing rate every 60 seconds to match available CFM. • Check air filter and duct system. • To clear, replace air filter if needed or repair or add additional ducting. Two-stage controls will reduce firing rate to first stage.