We have used Siemer Heating & Cooling numerous times to work on our PTAC units for us. These are "packaged terminal air conditioners" and when they go out, the tenants do not have any cool air, or heat. I like the fact that Siemer is always available to us. That is very important to me. Their employees show up on time and are easy to get along with. And, they know what they are doing. As a company, Siemer Heating & Cooling is very dependable and reliable!