When I got my first car, my dad gave me one major piece of advice about it. He said no matter what, I should get my oil changed on a regular basis. If I did no other maintenance on the car, getting the oil changed will keep it running longer. Of course, I have done other maintenance on my car as well, but the oil change is something that I have never skipped. And he was right, over the years, I have owned a couple of cars and had no major issues with any of them. A regular oil change after every 5,000 miles kept my maintenance cost on my cars low. In addition to my car, I applied this concept to my HVAC unit. I get it checked at least once per year by a licensed HVAC technician. This advice did not come from my dad, instead it came from my first HVAC service guy when I was about 22 years old. I had just moved into a townhome and had no clue about HVAC maintenance. It wasn’t until the unit broke down and I had my first encounter with the HVAC tech that I learned all about HVAC maintenance. He explained that their filter should be changed every 3 months, and he even taught me how to remove and install the new air filter. And just like my dad did, he gave me one major advice that I still follow to this day. He told me that no matter what, I should get my HVAC serviced at least once per year. I have been doing that since I was 22 years old, and I have never had any major issues with my HVAC units.