37 Maintenance and repair services provided pursuant to warranty contracts on residential internal energy equipment systems, namely, HVAC equipment and ventilation systems and connections thereto, residential appliances, namely, water heaters, dishwashers, refrigerators, clothes washing machines, clothes dryers, garbage disposal units, and connections thereto, residential electrical wiring and connections thereto, namely, electric lines, fuse boxes, circuit breaker panels, electrical switches, and electrical receptacles, and residential natural gas and water plumbing and connections thereto, namely, plumbing lines, pipes, connectors, toilets, faucets, fixtures, drains, vents, and valves; HVAC and leak-detector installation and maintenance services