Contractors. Get Quotes and Book Instantly. NYSDOH Approved Backflow Tester Certification Courses NYSDOH Approved BackFlow Prevention Device Tester Certification Courses The Foreign Labor Certification Data Center is developed and maintained by the State of Utah under contract with the US Department of Labor, Office of Foreign. Heritage Plumbing & Heating, Inc. Auburn, . Heritage Plumbing & Heating, Inc. prescreened Air Conditioning Contractors, Electricians in Gambrills Auburn, NH.