The electronic control unit UNISTER is designed to regulate the temperature of a solid fuel boiler by opening and closing the valve that controls the air supply to the boiler. Additionally, the device manages the operation of the circulation pump. The controller performs the following functions: it maintains the set boiler temperature by controlling the air flap, supports the combustion process with the so-called purge function, automatically shuts off the control when the boiler is turned off, and closes the valve in case of a power interruption. Furthermore, it closes the air intake valve while the boiler is being filled and manages the COMFORT SYSTEM function of the central heating pump, which protects the pump from plaque formation. Other features include device protection against freezing and overheating of the boiler, indication of signs of damage to the temperature sensor, and display of motor damage. The screen brightness is adjustable and can be increased by changing the settings. There is an option to connect the CONTROL remote control with sound signal function (sold separately).

Technical specifications:

• Measured temperature range: from -9 °C to +99 °C
• Settable boiler temperature range: from +40 °C to +85 °C
• Hysteresis of the air intake flap lift: from 0 °C to 9 °C
• Temperature setting range of the central heating pump: from +35 °C to +70 °C
• Hysteresis of the central heating pump (on and off): 2 °C
• Blow-off setting (possibility to completely shut off the blow-off valve)
• Operation: 0-90 seconds
• Pause: 1-60 minutes
• Nominal supply voltage: 230 V, 50 Hz
• Fuse: 1.25 A
• Permissible power of the central heating pump: 100 W / 230 V
• Relative humidity: < 95 %
• Housing protection class: IP 40
• Insulation class: UND
• Complete shutdown mode
• Controller dimensions: 125 x 115 x 53 mm
• Ambient temperature: from 0 °C to +40 °C
• Automatic shutdown when there is no fuel in the boiler: Yes.