Pump regulator for solid fuel boilers RT ST-21 with display

Controllers for CH Pumps

Principle of Operation

The EU-21 regulator (with an LED display) is intended to control the CH water circulation pump. The regulator’s task is to switch the pump on when the temperature reaches the set value and to switch it off when the boiler cools down below the set hysteresis value. Such an operation mode prevents an unnecessary activation of the pump which makes it possible to save electricity, as well as extends the pump’s life and improves its reliability. The EU-21 regulator may also serve as a thermostat by switching the pump on after reaching the set temperature. The controller also has the anti-stop function which prevents the pump stagnation beyond season (the pump switches on approx. every 10 days for 1 minute). The anti-freeze function is additional protection designed to prevent water from freezing in the installation (when the temperature drops below 6°C, the pump is switched on permanently).

Functions Performed by the Controller:

Controlling the CH or DHW pump

May operate as a thermostat

Anti-stop function

Anti-freeze function

Controller’s Equipment:

CH temperature sensor

LED display