CONTROLLER PUMP REGULATOR ANTYSTOP ST-21 DHW TECH

ST-21 DHW

DHW pump controller

The ST-21 DHW regulator is a universal DHW controller designed for circulating pump management. The DHW pump controller is equipped with two temperature sensors, and its task is to switch on the pump if the temperature difference of the sensors exceeds the set value (T2-T1 ≥ Δ), if T2 ≥ the minimum threshold of pump switching.

The pump will be switched off when T2 ≤ T1 or T2 < the minimum threshold for switching on the pump – 2°C (constant hysteresis) or when T1 reaches the set temperature.

Where: T2 – boiler temperature, T1 – boiler temperature (buffer).

DHW pump controller – advantages of using

The DHW controller prevents unnecessary pump operation and unwanted cooling of the tank when the supply temperature drops. In this way, the DHW pump controller saves electricity and extends the life of the pump . The ST-21 DHW regulator is equipped with a system that prevents the pump from stagnating during a longer standstill. Every 10 days, the pump is switched on for 1 minute.

DHW controller – effective protection against freezing

An additional feature is the protection of the installation against freezing. When the temperature on the boiler or tank sensor drops below 6°C, the pump is permanently switched on. It will be switched off when the temperature in the circulation reaches 7°C.

Operation of the ST-21 DHW controller

The ST-21 DHW pump controller is a device on which the preview of sensor temperatures is changed by pressing the MINUS (boiler water temperature) and PLUS (boiler feed water temperature) buttons. The main menu of the DHW pump controller includes such functions as: manual operation, pump switching delta, switching threshold, switching threshold and factory settings.

DHW driver – installation

The installation of the device should be carried out only by a person with appropriate experience and appropriate permissions. The DHW pump controller sensor should be fixed with a cable tie and isolated from external factors with insulating tape.

Functions performed by the DHW controller:

• Pump control
• Antistop function
• antifreeze function
• control of voltage-free output

Equipment of the DHW pump controller:

• LED display
• two temperature sensors