This standard applies to electric storage water-heaters for household purposes. This standard does not apply to: - water-heaters using other sources of energy (e.g. solar energy); - water-heaters with more than one heated volume; - water-heaters without thermal insulation. The common modifications supplements, as far as necessary, test methods which shall be applied in accordance with the Commission's Directive, which is based on standing loss only, implementing Council Directive 92/75/EEC with regard to energy labelling of household electric storage water heaters. Clauses defining permitted tolerances to values declared by the manufacturer and control procedures for checking these declared values are added.