This might not be the best method in choosing a contractor. There are many resources when searching for the right contractor for your needs. The Yellow Pages or the internet is an avenue for basic information. But it IS in your best interest to go further and find out if the contractor is licensed. The licensing process requires the Contractor to pass a test proving that the Contractor has the knowledge to install and maintain your HVAC equipment. It also requires a bond and insurance in case of any damages that might occur to your property or the workers on site. Permits are necessary if new equipment is installed. The Heating & Cooling Contractors Associations (haccaomaha.org) has a listing of HVAC Contractors that hold a valid license in our area or just ask the contractor to show it to you. Another resource is the Better Business Bureau. They keep on file all complaints against contractors and if they have been resolved successfully. Last but maybe the most important ask neighbors and friends. They can tell you and show you what type of experience they had.