Central control unit for underfloor heating SCU209i front view Central control unit for floor heating SCU209i side view


The SCU209I is a wired central unit compatible with underfloor heating. With the control unit you can control up to eight wired thermostats, the boiler or the pump circulation function.



SCU 209I Temperature compensation
Temperature compensation Install an external temperature sensor and let the SCU209I central unit compensate for the temperature as measured by the sensor.
SCU 209I Precise control
Precise control The SCU209I has eight outputs with Normal-Close (ND) and Normal-Open (ND) function for wired room thermostats. Together with these, the temperature in each zone (room) will be precisely controlled.
SCU 209I Protects the installation
Protects the installation The SCU209I control unit can adapt the hot water temperature by opening the mixing valves to allow the return of cooled water for mixing with hot water. In this way, the plant pipes are protected and the water temperature does not exceed alarming thresholds.
SCU 209I System check
System check Correct operation of the system can be checked using the special "Installation Mode". This can be used to perform individual tests or check outputs.


Underfloor heating
280 x 110 x 40 mm
Power supply
230 VAC +10/-10%, 50 Hz
Maximum load pump and thermal actuators
Division Gas
Central relay
Dry contact max. 4A
Relay X
max. 4A, contact dry
Thermal actuator
8 x 230V
Mixing valve relay
SPDT 230V 8A
Additional functions
Optional timer/switch for night, Optional timer/switch for water flow protection, Open terminals for no water supply, Open terminals for NSB, Closed terminals for sufficient water supply, Closed terminals for day operation
Power supply water temperature sensor
NTC 100K
Outdoor temperature (weather) sensor
NTC 100K
High temperature limit sensor
NTC 100K
2 years

Frequent questions

What does the "E2" error on the SCU209I display indicate?
When "E2" is shown on the display, the external sensor is faulty or short-circuited.
What does the "E4" message on the SCU209I control unit display indicate?
"E4" will alarm about insufficient water in the installation.
Why is "E1" displayed on the SCU209I control unit screen?
The water in the installation must not exceed 55°C. If the water temperature is higher than the allowed limits, "E1" will be shown on the display.
"E3" is displayed on the SCU209I screen, why?
"E3" sounds an alarm on the external output temperature - it is above the maximum limit.
What does "E5" indicate on the display of the control unit?
"E5" will appear when the SCU209I is not heating - basically, the water temperature is below the set lower limit after heating has been activated for 15 minutes.
Central units for control


Product code: 3710070
Wired central control unit
  • Temperature compensation
  • Precise control
  • Protects the installation
  • System check