This European Standard applies to resettable line-type heat detectors consisting of a sensing element using an optical fibre, a pneumatic tube or an electrical sensor cable connected to a sensor control unit, either directly or through an interface module, intended for use in fire detection and fire alarm systems installed in and around buildings and other civil engineering works (see EN 54-1:2011). This European Standard specifies the requirements and performance criteria, the corresponding test methods and provides for the Assessment and Verification of Constancy of Performance (AVCP) of resettable line-type heat detectors to this EN. This European Standard also covers resettable line-type heat detectors intended for use in the local protection of plant and equipment. Resettable line-type heat detectors with special characteristics and developed for specific risks are not covered by this EN. This European Standard does not cover line-type heat detectors that are based on non-resettable, fixed temperature electrical cables (so called digital systems).