The new Energy Label applies to all water heaters – whether electrical, gas or oil; instantaneous water heaters, small water heaters, wall mounted cylinders, DHW heat pumps, solar cylinders or indirect cylinders. The rating system for DHW appliances categorises them into seven efficiency classes. "A" is the highest energy efficiency class. G denotes appliances with extremely poor values. STIEBEL ELTRON products are almost exclusively in the top groups. For example, our instantaneous water heaters and small water heaters meet the criteria for future label category A, which is the highest possible rating. Other products, such as our wall mounted cylinders, use high quality electronics or ECO functions, making operation particularly economical.