Two boards, local plumbing inspectors
The Plumbers' Examining Board licenses plumbers in Maine, while the Maine Fuel Board covers technicians who work on oil, propane and natural gas equipment. Both are part of the Office of Professional and Occupational Regulation. A water heater installation needs an internal plumbing permit from the town's local plumbing inspector, so even small towns have someone responsible for signing off.
Lake water, wells and oil-fired hot water
Portland and its neighbors drink very soft, unfiltered Sebago Lake water from the Portland Water District, which means little scale but quicker wear on anode rods. Out in the towns, private wells are common, and Maine well water often brings iron, manganese, arsenic or radon along with it. Across the state, oil boilers with tankless coils or indirect tanks still supply much of the hot water, and Efficiency Maine has at times offered rebates that made heat pump water heaters a popular replacement. Smaller repairs in Maine usually run $175 to $700, and a standard tank swap commonly falls between $1,700 and $3,400; see water heater replacement.