The cwu pump controller ST-21 by TECH-STEROWNIKI, code WG.14.0115, is designed to improve the operation of the pump in central heating systems. It prevents unnecessary pump operation and unwanted cooling of the tank when the supply temperature decreases.

• ANTYSTOP function: Activates the pump approximately every 10 days for 1 minute.
• Frost protection: Permanently activates the pump when the temperature at the sensor drops below 6°C and deactivates it at 7°C.
• Temperature indication: Performed with the MINUS button (water temperature in the water heater) and PLUS button (water supply temperature at the boiler).
• Intermediate functions: Manual operation, pump activation delta, activation and deactivation limits, and factory settings.
• Installation: Must be carried out by a person with appropriate experience and licenses.
• Sensor: Fixed with a cable tie and insulated with insulating tape.
• Available features: Pump control, voltage-free output control, LED display, and two temperature sensors.