# The Boiler (Efficiency) Regulations 1993, Paragraph 9


In Part I of this Schedule “back boiler” means a boiler designed to supply hot water for central heating and to be installed in a fireplace recess as part of a back boiler/gas fire combination;
“boiler to be installed in the living space” means a boiler with an effective rate of output of less than 37 kW which —
(a) is designed to provide heat to that part of the living space in which it is installed by the emission of heat from the casing,
(b) has an open expansion chamber,
(c) is capable of heating water using gravity circulation.

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Source: https://www.legislation.gov.uk/uksi/1993/3083/schedule/3/paragraph/9 (the official version)
Page: https://openlegislation.uk/boiler-efficiency-regulations-1993/schedule-3/paragraph-9
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.