Maine to Delaware: master HVAC technician license reciprocity

Delaware issues a person-held Master HVACR license through the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners in the Division of Professional Regulation (the electrical trade is regulated by a separate board). A Master HVACR licensee may design, install, service and alter heating, air conditioning, refrigeration, ventilation and process systems including gas piping; a Master HVACR Restricted license covers one specialty (forced-air heating with ventilation and gas piping, hydronic heating with gas piping, commercial hood systems, refrigeration, air conditioning, or gas piping). Employees work under a master's supervision without their own license. A new master needs a journeyman certificate from a federally-registered apprenticeship plus 2 years under a master, or 7 years under a master plus the ABC Delaware Apprenticeship By-Pass exam, then passes the ProV-administered Master HVACR exam (100 questions, 4 hours, open book, 70%, $100) and pays the $173 application fee; a CFC (EPA 608) card is required. Out-of-state masters are licensed by reciprocity without a Delaware exam under 24 Del. C. § 1823: the Board has published that Connecticut and Maryland standards are substantially similar (no experience proof) and that fourteen other jurisdictions are not (7 years of licensed practice required); all other states are evaluated case by case. Licenses renew biennially with 5 hours of continuing education from 2026.

Maine has no master HVAC, HVAC contractor, mechanical contractor or refrigeration license at the state or municipal level, and no general contractor license, so a business may install and service air conditioning, ductwork, ventilation and refrigeration without any state credential. The highest person-held credential in the heating trades is the Maine Fuel Board's Master Oil Burner and/or Solid Fuel Technician license ($200 plus a $21 background check, exam required, after four years licensed with at least two as a journeyman), which is the license that lets a technician work unsupervised on oil and solid-fuel burning equipment and supervise apprentices; propane and natural gas work needs the separate Propane and Natural Gas Technician license, which has no master tier. Under a 2013 memorandum of understanding between the Fuel Board and the Electricians' Examining Board, master and journeyman oil burner technicians may also wire mini-split heat pumps of 36,000 BTU or less in one- and two-family dwellings and existing multi-family dwellings with electric heat; larger units and other occupancies require a licensed electrician, and refrigerant handling requires federal EPA Section 608 certification. A master HVAC licensee arriving from another state gains nothing from that license in Maine: no Maine agency recognizes it, no reciprocity exists for any Fuel Board license, and the Fuel Board's rules only credit documented out-of-state employment toward the master oil burner qualifications before the applicant sits the Maine exam. A statutory licensure-by-endorsement route (32 M.R.S. s. 18142-A and 10 M.R.S. s. 8003-H) applies to Fuel Board licenses in principle, but the board has not published an endorsement procedure or a list of equivalent states.