Each time in the spring, I purchase a service contract through ClimateSmith LLC. With this, they come out two times a year to check my heating and cooling. In the spring they make sure my air conditioning system is running fine, and in the fall they go over my heating system. I have been using them for several years now and I have been very pleased. I like the price and I like the technicians who come around to provide the service. I have no problems with them or my equipment. I will continue with them because I like what they do, and for me, it's worked out really well.