The Fan Coil Unit Controller is used to control fan coil units, floor heating or switch actuators. Depending on the design of the device, fan coil units are used in 2-pipe or 4- pipe systems. It controls up to 3 fan speeds (Relay or 0- 10V outputs) as well as heating or cooling valves (Proportional or electrothermal valve) respectively. The mode of control is based on two-step control or a time- discrete PI controller with setpoint/actual value comparison. The valves and the fan can be regulated directly by devices via the closed loop of this controller. When the Fan Coil Unit Controller is used in floor heating, it can control up to seven channel. All of the floor heating channel control is used a time-discrete PI controller with setpoint / actual value comparison.