Electrothermal actuator S55174-A101 STA23
Electrothermal actuator S55174-A101 STA23 Electrothermal actuator S55174-A101 STA23 diagram with dimensions


  • Height: 74mm
  • Width: 44mm
  • Length: 65mm

Power supply

  • Operating voltage: AC 230V±15%
  • Frequency: 50/60Hz
  • Power consumption at 50Hz: operation 2.5W (at power-up 58VA)
  • Switch-on current (transient): 250mA

Operating data

  • Positioning time at 20°C, 50Hz: 210s
  • Perm. temperature of medium in the connected valve: 1…110 °C
  • Operating temperature of medium: 5…50°C

Electrothermal Actuator S55174-A101 STA23

STA23 valve actuator is used for radiators, small and Combi valves.


  • Operating voltage AC230 V, 2-point positioning
  • Positioning force 100N
  • Standard version with connecting cable (1m/ 0.8m)
  • 270° visible position indication
  • Mounting using a sliding sleeve lock (bayonet)
  • Adaptor for mounting on third-party valves
  • Automatic adaption of close – dimension
  • IP54
  • Robust, maintenance-free, noise-free
  • Can be used in interior rooms
  • Are used with Siemens radiator valves VDN, VEN and VUN

Actuator operation

Electrothermal actuators STA23 are noise-free ad do not require maintenance. When control signal is applied to the actuator, the temperature of the heating element rises, which causes the solid expansion medium to expand. It transfers its stroke directly to the installed valve.