Annex I Definitions applicable for Annexes II to V United Kingdom Original text. Later amendments are not shown. For the purposes of Annexes II to V the following definitions shall apply: Definitions related to heaters Definitions related to boiler space heaters, boiler combination heaters and cogeneration space heaters Definitions related to heat pump space heaters and heat pump combination heaters Definitions related to water heating in combination heaters ← Signature Annex I Division →