Question to the Department for Business, Energy and Industrial Strategy:

To ask the Secretary of State for Business, Energy and Industrial Strategy, pursuant to his Answer 11 June 2019 to Question 258961 on Boilers, whether the variables listed in that answer apply to the heating system and not the boiler.

The variables stated in the answer to Q258961 on 11 June 2019, apply to the in situ test context for the boiler, not to the heating system. The required test conditions for the boiler are described in BS 15502-1, sections 8.1.1 and 8.1.2, unless otherwise specified elsewhere in the standard for specific cases. These conditions include for example requirements on the preparation of test gases, test pressures, test room ventilation, ambient temperature, protection from solar radiation, physical mounting conditions, measurement conditions and tolerances, insulation of the test rig, establishment of thermal equilibrium, conditional control settings and several other similar items requiring closely controlled test room conditions.