The Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners issues master plumber, master HVACR and master restricted HVACR licenses. Restricted licenses limit practice to a specialty such as air conditioning. The primary objective of the Delaware Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners is to protect the public from unsafe … Continue reading HVACR