22 34 36 Commercial gas domestic water heater
22 33 30.26 Residential, collector-to-tank, heat-exchanger-coil, solar-electric domestic water heater
22 33 30 Residential electric domestic water heaters
22 33 33 Light commercial electric domestic water heater
22 34 30 Residential gas domestic water heaters
22 33 30.16 Residential storage electric domestic water heaters