Welding cap cooling water controller and method of controlling a welding cap cooling water controller

A method of controlling a welding cap cooling water controller, comprising:

• providing a cooling water pipe which includes a cooling water inlet leading towards at least one welding cap and having a switchable inlet valve for closing the cooling water inlet and a cooling water return leading away from the at least one welding cap and having a switchable return valve for closing the cooling water return, a section of the cooling water pipe that is arranged downstream of the inlet valve and upstream of the return valve forming a test section of the cooling water pipe;
• providing a pressure sensor that is configured for pressure measurement of the cooling water in the test section;
• providing a control unit that is coupled to the pressure sensor, the inlet valve and the return valve for signal transmission;
• increasing pressure of cooling water in the test section to an overpressure that is above a supply pressure which prevails in the test section during a welding process with the inlet valve open and the return valve open;
• and
• performing a pressure drop measurement at the overpressure.