Complete 1 system furnace repair and preventative maintenance check. Found a 16-year-old system. Blower and ductwork are very dirty and causing unnecessary stress on the system. Both need to be cleaned. Heating elements are working properly. The system is missing a secondary water safety devices as well as air purification. Needs inline float switch and electrostatic filter and UV light inhibitor to kill mold and bacteria in the house and keep system cleaner longer.