Achieving the highest energy efficiency star rating for Gas Storage, these units offer both environmental benefits and cost savings. Gas Storage systems maintain heated water at a consistent temperature in an insulated tank, readily available for use. When the temperature drops below the thermostat setting, the water is reheated by a gas flame. These systems are available in both internal and external models, with internal models requiring a flue for ventilation. The storage capacity and recovery rate determine the amount of hot water they can deliver per hour. Due to the faster heating capability of Gas systems compared to Electric ones, Gas Storage units typically require a smaller tank sise to produce the same amount of hot water per hour.