Came out to perform maintenance on furnace. Customer met me at front door and showed me location of system. I inspected the filter, blower assembly, motor, electrical components, heating components, evaporator coil, heat exchanger and overall condition of equipment. Changed filters for customer. Blower capacitor is reading slightly out of tolerance, customer doesn’t want to do anything about at this time. Heat exchanger has some wear, but nothing concerning. Cleaned flame sensor and dust off the burners and components. Checked operation, amps, temperatures and gas pressure. System is heating properly at this time. Would recommend duct cleaning, but the type of ductwork seems brittle and might not be able to be cleaned.