Upon arrival found a 12 year old Goodman furnace. Measured heat rise and found system was over heating. Static was high. Heat exchanger had hot spots. There is a concern it can fail soon. Indoor blower compartment was completely dirty. Pulled blower and cleaned it out. Went over filtration upgrade options with client. Clients said they have serious dust issues. Utility bills were low. ***solar***. Blower motor is inefficient due to age. Ignition components are looking worn down. Informed client of condition of unit. System is operational upon departure.