A method of controlling a system (100, 100', 100") including a heating arrangement for heating a process medium, a current sensing arrangement, and a switching arrangement configured to selectively couple a power supply to the heating arrangement, the switching arrangement comprising at least one semiconductor switch (120A, 120B, 120C), the method comprising: in response to a demand signal for starting heating of the process medium, operating the system in a test mode, wherein operating the system in the test mode includes performing a test sequence (230A, 230B) comprising: controlling (232A, 232B) the switching arrangement to couple the power supply to the heating arrangement for a predetermined period; monitoring (234A, 234B) an electric current through the heating arrangement during the predetermined period using the current sensing arrangement; comparing (236A, 236B) the monitored electric current to an electric current threshold during the predetermined period; characterized by: switching the system from operation in the test mode to operation in a heating mode if the monitored electric current remains below the electric current threshold for a duration of the predetermined period; and switching the system from operation in the test mode to operation in a dormant mode (210, 220) if the monitored electric current meets or exceeds the electric current threshold during the predetermined period, wherein: operation of the system in the heating mode includes controlling the switching arrangement to couple the power supply to the heating arrangement for heating the process medium to achieve a target temperature and/or to maintain the process medium at the target temperature, and operation of the system in the dormant mode includes controlling (212, 222) the switching arrangement to decouple the power supply from the heating arrangement. controlling (232A, 232B) the switching arrangement to couple the power supply to the heating arrangement for a predetermined period; monitoring (234A, 234B) an electric current through the heating arrangement during the predetermined period using the current sensing arrangement; comparing (236A, 236B) the monitored electric current to an electric current threshold during the predetermined period; characterized by: switching the system from operation in the test mode to operation in a heating mode if the monitored electric current remains below the electric current threshold for a duration of the predetermined period; and switching the system from operation in the test mode to operation in a dormant mode (210, 220) if the monitored electric current meets or exceeds the electric current threshold during the predetermined period, wherein: operation of the system in the heating mode includes controlling the switching arrangement to couple the power supply to the heating arrangement for heating the process medium to achieve a target temperature and/or to maintain the process medium at the target temperature, and operation of the system in the dormant mode includes controlling (212, 222) the switching arrangement to decouple the power supply from the heating arrangement. switching the system from operation in the test mode to operation in a heating mode if the monitored electric current remains below the electric current threshold for a duration of the predetermined period; and switching the system from operation in the test mode to operation in a dormant mode (210, 220) if the monitored electric current meets or exceeds the electric current threshold during the predetermined period, wherein: operation of the system in the heating mode includes controlling the switching arrangement to couple the power supply to the heating arrangement for heating the process medium to achieve a target temperature and/or to maintain the process medium at the target temperature, and operation of the system in the dormant mode includes controlling (212, 222) the switching arrangement to decouple the power supply from the heating arrangement. operation of the system in the heating mode includes controlling the switching arrangement to couple the power supply to the heating arrangement for heating the process medium to achieve a target temperature and/or to maintain the process medium at the target temperature, and operation of the system in the dormant mode includes controlling (212, 222) the switching arrangement to decouple the power supply from the heating arrangement.