Why does your furnace sometimes stop heating and then start working again? Intermittent issues often point to dirty blower wheels or clogged air filters putting strain on your system. Learn more about preventive maintenance by scheduling a heating inspection with Keep Smiling. Our Loganville technician evaluated this Lennox furnace and found a dirty blower wheel affecting airflow, plus we recommended UV light installation to improve indoor air quality. Regular tune-ups catch small problems before they become costly repairs.