As a homeowner, hiring a HVAC technician to work on your heating, ventilation and cooling system is a task you will most likely have to do at some point. There's a great deal of danger involved with HVAC equipment and a lot can go wrong, so it's important to only hire a licensed HVAC technician for work around the home.

Licensing information

A license provides proof that the technician has been professionally trained. Each state has different licensing requirements, so check with your state's professional licensing department to check the status of a license.

NATE certification

The North American Technician Excellence (NATE) certification is a nationally recognized and respected certification for heating, ventilation, air conditioning and refrigeration technicians. The certification is not legally required to become a technician, but it is widely recognized in the field and validates a technician's knowledge. In order to receive this certification, technicians must pass a knowledge-based exam. This certification can be earned in one or more specialty areas, including air conditioning, gas furnaces and air distribution.

Excellence certification

The HVAC Excellence certification is another prominent certification in the industry. Technician certifications include the professional level and the master specialist level. To earn the professional-level credential, a contractor must first have two years of field experience and pass a comprehensive exam in specialty areas, such as residential air conditioning and heat pump service. Contractors who pass their exams receive a chevron for their specific certification area, a HVAC Excellence patch and a wall certificate. The master specialist credential requires contractors to have at least 3 years of verifiable field experience and a passing score on the HVAC Excellence professional-level technician exam.

EPA 608 certification

The Environmental Protection Agency (EPA) now requires all people with access to a system or container that stores refrigerant to have the Environmental Protection Agency (EPA) 608 certification. A HVAC technician cannot legally buy refrigerants without this credential. There are three types of certification available, and contractors must pass a written examination to gain this credential. The first level of  certification allows a technician to handle small appliances containing less than 5 pounds of refrigerant, such as window air conditioning units. The second allows technicians to handle products containing high pressure refrigerants. Type-three certification allows a technician to handle products containing low-pressure refrigerant.

For more information, visit the Angie's List Guide to Heating and Cooling.