Applies to electrically operated commercial water boilers and liquid heaters for the boiling or heating of liquids to be used in the preparation of beverages and not intended for household use. Does not apply to: appliances with electrode heaters; appliances designed exclusively for industrial purposes; appliances meant to be used in locations where special conditions prevail. Covers the electrical part of appliances making use of other forms of energy. Coverage includes definitions, marking, endurance, construction, components, heating, and moisture resistance.