Responded to service call for Lennox Elite Series furnace with intermittent ignition failures requiring daily resets. Diagnosed and cleaned corroded flame sensor, inspected heat exchanger, and verified all electrical components were within specifications. Furnace subsequently operated properly with normal heating function. Identified minor water leak from collector box and presented repair options to homeowner. Customer declined immediate collector box repair but may consider complete system replacement in summer due to unit's 20-year age.
