Electronic surface-mounted climate controller for controlling heating/cooling in 2- and 4-pipe systems for hotels, residential properties and business premises. Up to 5 valve actuators (24V~, closed when de-energised or open when de-energised) can be controlled for each output. Especially suitable for controlling cooling ceilings due to the option of dew point monitoring via optional external dew point sensors. In order to compensate for the inertia of control paths with cooling ceilings, the device has a temperature sensor input for activating an external radiation sensor (optional). As a variant for public authorities that need the controller to be inaccessible to unauthorised people, the external sensor can also be implemented as a room sensor (optional). Using an internal Poti adapter, internal or external sensors, or both sensors, can be selected using adjustable weighting. The factory preset “zero point” of approx. 21…°C can be adjusted by +/- 5K in the device. The adjustment knob can be used to adjust the set temperature within the range +/- 3K of the set zero point. Contact inputs for ECO function and OFF (frost protection). In 2-pipe mode, the controller is operated with a combined heating/cooling output, which is switched via an external contact (changeover contact) or upstream sensor. Using a changeover contact and parallel wiring, it is possible to achieve central switching for up to 20 controllers. Contact opened and/or supply temperature < 20...°C = cooling mode, contact closed and/or supply temperature > 26…°C = heating mode.