The Qualifications to Give You Peace of Mind At A-PLUS Service Experts Heating & Air Conditioning in Waldorf, we’ve been helping the community since 1976 and all of our technicians and equipment installers are licensed, highly qualified and NATE-certified. We encourage you to learn about NATE certification and all it involves. It’s a highly-touted credential that our service folks have earned through study, know-how, extensive training and testing. So if you should need HVAC service or repair, don’t just call some guy with a few wrenches and a truck. Call 301-747-3140 for A-PLUS Service Experts Heating & Air Conditioning in Waldorf. We have all of the best qualifications to provide expert furnace and AC repair and service. And all of our work is 100% guaranteed for a full year!