Description
Introduction
The Möhlenhoff OEM Alpha direct display 230 V offers direct and precise temperature control for your room thanks to the digital display and simple operation. As a result, you enjoy maximum comfort and energy efficiency. On the one hand, the integrated frost and valve protection prevents problems at low temperatures, while on the other hand the adjustable setpoint limit ensures reliable safety. All in all, this makes it a smart choice for both standalone control and system integration!
Main Benefits
- Direct connection of valve actuators – ideal for single-room control
- Push-turn adjustment knob with fine calibration – for precise temperature setting (5–30 °C)
- Clear, multilingual display – always easy to read, even in the dark
- Frost and valve protection function – prevents freezing and valve damage
- Time and switching signal inputs – flexible for day/night setback or cooling/heating switch
- Compact and flat design – modern appearance, fits almost anywhere
Technical Specifications
| Property | Value |
|---|---|
| Supply voltage | 230 V ±10 %, 50 Hz |
| Measurement range | 5 – 30 °C |
| Resolution | 0,25 °C |
| Max. valve actuators | 5 (at 1 W each) |
| Output rating | 2 A resistive / 200 VA inductive |
| Housing | ABS, color pure white, dimensions 86×86×31 mm |
| Protection | IP20, protection class II |
| Functions | Frost protection, valve protection, setpoint limitation, setpoint calibration |
| Inputs | Setback, heating/cooling changeover |
| Operation | Push-turn rotary knob with fine adjustment |
Available Variants
230 V Version: Standard with digital display
| Item name | Description |
|---|---|
| RD 20203-11N4 | Heating, NC version, fixed reduced temperature, temperature setback input, switching output display, setpoint calibration and limitation, valve protection, switching output can be disabled, frost protection, operating lock, signal white color RAL 9003 |
| RD 20203-11N5 | As RD 20203-11N4 but including design panel |
| RD 20203-11N3 | As RD 20203-11N4 but in deep black color RAL 9005 |
230 V Version: Comfort with digital display and heating and cooling function
| Item name | Description |
|---|---|
| RD 25203-40N4 | Heating/cooling, NC/NO version, changeover, selectable heating system, adjustable reduced temperature, temperature setback input, switching output display, setpoint calibration and limitation, cooling lock function, valve protection, switching output can be disabled, frost protection, operating lock, backlighting, signal white color RAL 9003 |
| RD 25203-40N5 | As RD 25203-40N4 but including design panel |
| RD 25203-41N3 | As RD 25203-40N4 but in deep black color RAL 9005 |
230 V Version: Controller with digital display, heating and cooling function and temperature schedule
| Item name | Description |
|---|---|
| RD 25203-60N4 | Heating/cooling, NC/NO version, changeover, selectable heating system, Smart Start/Stop, temperature setback output, adjustable reduced temperature, switching output display, setpoint calibration and limitation, day and night setpoint setting, cooling lock function, valve protection, switching output can be disabled, frost protection, operating lock, backlighting, pilot timer output, integrated and configurable temperature schedule, signal white color RAL 9003 |
| RD 25203-60N5 | As RD 25203-60N4 but including design panel |
| RD 25203-61N3 | As RD 25203-60N4 but in deep black color RAL 9005 |
Available Options
| Feature | Description |
|---|---|
| Mounting base | Customizable in color and design |
| Design panel | High-quality front panel for room control with display |
| display | Backlighting for standard version |
Available Accessories
| Item name | Description |
|---|---|
| ES 1000 | NTC temperature Sensor, 3 m cable, 2 x 0.75 mm², for connection to Alpha direct Control, measuring range 0–50°C, protection IP67, maximum measuring voltage 12 V, NTC resistance 22k Ohm at 25°C ± 2%, suitable for 230 V applications |
FAQ
What is the adjustment range of this thermostat?
The adjustment range is between 5 °C and 30 °C; in addition, you can limit the setpoint so that the temperature does not rise above or fall below a predefined value.
Can I connect the thermostat to my existing valve actuators?
Yes, since the thermostat directly supports up to 5 valve actuators of 1 W, it works seamlessly with the most common valve systems.
Is this thermostat suitable for both heating and cooling?
Unlike the standard version, the Comfort and Control version offers a cooling function with changeover input, allowing you to switch easily between heating and cooling.
Does the display work in the dark as well?
The digital display has backlighting, so you can clearly read all symbols and values even in dark rooms.
How is the installation carried out?
The flat and compact housing allows both surface-mounted and flush-mounted installation. Meanwhile, power is supplied via 230 V, either directly or via the Alpha Basis unit.
Does the thermostat support night setback?
Yes, on the other hand there is a timer input for time-controlled reduction of the room temperature, ideal for night or absence programs.
Do you have any questions or would you like more information? Please contact us! You can reach us by phone, email or, also nice, via the chat function.