We are on Bethke's plan to have them look at our furnace in the fall and AC in the spring/summer. Let me tell you. This is TOTALLY worth it. We're pretty novice homeowners who know nothing about HVAC. Having them call me to set up the appointment, bringing the air filters, cleaning the AC and checking everything (that I know absolutely nothing about) and tuning everything up, provides so much reassurance and makes me feel like I'm winning at adulthood. Totally worth it. Not only that but every time they've come they've taught me something about our system, how we could run it more efficiently and tips or tricks on keeping our heating and cooling bills lower. The plan that we're on also is almost like insurance. If something happens (furnace or AC go out), we get a discount or flat rate for them to come service it for us. The technicians are so smart and knowledgeable. There is so much added value to having them come and tune up your HVAC. Beyond impressed with their service.