For this job, I work on a super tune-up on this gas furnace system. I went through all the mechanical and electrical parts of the system and checked for maximum efficiency. Filter was replaced, outside condenser was washed, and refrigerant levels were on point. UV bulb replacement was recommended to customer, customer did not know if she had a UV system in her unit, I explained to the customer what it was for, customer rejected UV bulb. Thank you for choosing Comfort experts, have a great day!