This document specifies inspection procedures for the assessment of energy performance of existing boilers and heating systems. Heat generators types covered by this standard are: ¾ð boilers for heating, domestic hot water or both; ¾ð gas, liquid, solid fuel fired combustion boilers; ¾ð electrically driven and gas driven heat pumps; ¾ð thermal solar systems for domestic hot water, heating or both; ¾ð other heat generators types, such as cogeneration units. Parts of heating systems covered by this standard are: ¾ð heat generators, including generation control; ¾ð heating distribution network, including associated components and controls; ¾ð heating emitters, including components and controls; ¾ð space heating control system; ¾ð heat storage and associated components; ¾ð domestic hot water production system. This standard covers issues related to energy conservation and environmental performance.