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Electric heat pump water heater means a water heater that uses electricity as the energy source, has a maximum current rating of 24 amperes (including the compressor and all auxiliary equipment such as fans, pumps, controls, and, if on the same circuit, any resistive elements) at an input voltage of no greater than 250 volts, has a rated storage capacity of 120 gallons (450 liters) or less, is designed to transfer thermal energy from one temperature level to a higher temperature level for the purpose of heating water, including all ancillary equipment such as fans, storage tanks, pumps, or controls necessary for the device to perform its function, and is designed to heat and store water at a thermostatically-controlled temperature less than or equal to 180 [deg]F (82 [deg]C).
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Electric instantaneous water heater means a water heater that uses electricity as the energy source, has a nameplate input rating of 12 kW (40,956 Btu/h) or less, contains no more than one gallon of water per 4,000 Btu per hour of input, and is designed to provide outlet water at a controlled temperature less than or equal to 180 [deg]F (82 [deg]C). The unit may use a fixed or variable burner input.
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Electric storage water heater means a water heater that uses electricity as the energy source, has a nameplate input rating of 12 kW (40,956 Btu/h) or less, has a rated storage capacity of 120 gallons (450 liters) or less, contains more than one gallon of water per 4,000 Btu per hour of input, and may be designed to heat and store water at a thermostatically-controlled temperature less than or equal to 180 [deg]F (82 [deg]C).
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Gas-fired heat pump water heater means a water heater that uses gas as the main energy source, has a nameplate input rating of 75,000 Btu/h (79 MJ/h) or less, has a maximum current rating of 24 amperes (including all auxiliary equipment such as fans, pumps, controls, and, if on the same circuit, any resistive elements) at an input voltage of no greater than 250 volts, has a rated storage volume not more than 120 gallons (450 liters), and is designed to transfer thermal energy from one temperature level to a higher temperature level to deliver water at a thermostatically controlled temperature less than or equal to 180 [deg]F (82 [deg]C).
Gas-fired instantaneous water heater means a water heater that uses gas as the main energy source, has a nameplate input rating less than 200,000 Btu/h (210 MJ/h), contains no more than one gallon of water per 4,000 Btu per hour of input, and is designed to provide outlet water at a controlled temperature less than or equal to 180 [deg]F (82 [deg]C). The unit may use a fixed or variable burner input.
Gas-fired storage water heater means a water heater that uses gas as the main energy source, has a nameplate input rating of 75,000 Btu/h (79 MJ/h) or less, has a rated storage capacity of 120 gallons (450 liters) or less, contains more than one gallon of water per 4,000 Btu per hour of input, and is designed to heat and store water at a thermostatically- controlled temperature less than or equal to 180[emsp14] [deg]F (82 [deg]C).
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Oil-fired instantaneous water heater means a water heater that uses oil as the main energy source, has a nameplate input rating of 210,000 Btu/h (220 MJ/h) or less, contains no more than one gallon of water per 4,000 Btu per hour of input, and is designed to provide outlet water at a controlled temperature less than or equal to 180[emsp14] [deg]F (82 [deg]C). The unit may use a fixed or variable burner input.
Oil-fired storage water heater means a water heater that uses oil as the main energy source, has a nameplate input rating of 105,000 Btu/h (110 MJ/h) or less, has a rated storage capacity of 120 gallons (450 liters) or less, contains more than one gallon of water per 4,000 Btu per hour of input, and is designed to heat and store water at a thermostatically-controlled temperature less than or equal to 180[emsp14] [deg]F (82 [deg]C).
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