An HVAC contractor working on furnace installation needs to be licensed. This licensing can be handled either at the state or at the local level. This will depend mostly on the way these laws are applied in your state. You can contact your local building inspector to learn more about required licensing for contractors.

You should always get references for any contractor before you hire him or her. These references are best if they're from a local person who has used the services of the contractor in the past. Local references will tell you how well the contractor understands local climate conditions. An understanding like this will help your contractor to install a more useful furnace system in your home.

Always ask for an estimate from the contractor. You should never allow the contractor to get to work without getting an estimate. If a contractor is unable to provide you with an estimate, then he or she may be unqualified to work for you.