For years I would reliably call my local Chicago A/C maintenance company for seasonal service.
I would have an appointment every Spring plus allow them to scrub the inner workings.
They would wash, wipe, scrub, plus then leave. There was never an A/C maintenance or anything major. I started wondering what I was paying for, then you can’t actually see it, just tak ethier word for it. So I then made the house to no longer do A/C service. After two years of missing maintenance my unit got back at me. The system totally shut down plus would not turn on. It was the middle of my summer time celebration where I had a whole crop of people. I had to call for Chicago A/C emergency maintenance on a weekend. That added cost alone made me all sweaty plus nervous. I then had to navigate an A/C professional during a celebration, on a weekend, in a hot house. It was horrible. The guy showed me how gross my system was inside. There was also a worn part that had given out that needed replacing. The cleaning, lubricating, oiling, plus fixing all took hours to repair. By that point almost everyone had left because my house was so hot. The cost of the bill was obscene. The guy said I could have prevented it all with routine A/C service. I right away made sure to enroll in cooling maintenance again so that an emergency maintenance never happened to me. It would have been cheaper to pay for maintenance for two years then that one repair. It was a dumb decision on my part.