Diagnosed and serviced 10+ year old Westinghouse furnace (Model M3RI 060A AW) with intermittent no-heat condition. Found completely plugged condensate drain causing water backup into collector box and inducer motor, which triggered the inducer motor limit to shut down system operation. Cleared blocked drain line to restore proper drainage. Inspection revealed advanced rust on heat exchanger, leaking collector box, and corroded burners causing inconsistent ignition across all burners. System is operational after service but showing significant age-related deterioration.
