A leak detection device for a water installation

A leak detection system for a water installation is disclosed. The leak detection system comprises a first temperature sensor (TS1) configured to provide a first signal representative of a first temperature T1 measured by said first temperature sensor; a second temperature sensor (TS2) configured to provide a second signal representative of a second temperature T2 measured by said second temperature sensor; a heating element (HE) and a control unit (CU). The first temperature sensor (TS1), said second temperature sensor (TS2) and said heating element (HE) are mounted onto a surface of a water pipe (P) in said water installation. The first temperature sensor (TS1) is configured to communicate a first temperature T1 to the control unit and the second temperature sensor (TS2) is configured to communicate a second temperature T2 to the control unit. The control unit (CU) is configured to apply the first temperature T1 and said second temperature T2 as input in a calculation of a leak value LV, according to a predetermined calculation method. Depending on the magnitude of the calculated leak value LV the control unit (CU) is able to distinguish between situations of water consumption, situations of no water consumption but leak, and situations of no water consumption and no leak in the water installation.