Open space and gutter heating controller, incl. exchangeable and traversable sensors, is used for fully automatic heating of open spaces, garage driveways, ramps and outdoor stairs, etc. The control system determines the optimum switch-on time in order to prevent ice formation at an early stage, i.e. before the freezing point. Since the unit is only switched on when there is a risk of ice formation, unnecessary waste of energy is avoided. The unit has a standard factory program. A digital display of the set and actual values and the parameters to be set. Automatic sensor detection and monitoring. Adjustable reheating as well as an operating hours counter for the heating and other functions. Suitable for DIN rail mounting.