Pressure switch was stuck closed when I arrived. I blew out the air tubes and tested pressure switch. After doing that the furnace ran for 15 minutes and then I made the furnace restart three more times. Furnace operated without issue. Furnace is 18 years old and the blower sounds like it’s about to give out. After talking with customer, they are looking to have some extra ductwork done and so I mentioned possibly doing a bundle deal with the furnace as well. Customer would like to see all options before deciding what to do.