Two circles secondary without mixing valve heating system 5/4"

Two circles secondary without mixing valve heating system 5/4"
1 929

Industrial heating system for radiator and floor heating -

Without mixing valve

Content of package:

  • Heating pump unit without mixing valve (2 pieces)
  • Euroster UNI2 controller
  • 2-way insulated distributor 5/4"


2-way unmixed pump unit 5/4"


DN32 pump units, thanks to a very careful measuring of the specific components, have all the force points of range, such as functional capacity, reliability and versatility of installation.


They can be connected to heating systems with powers up to 111 kW, with a very low energy consumption assured by high efficiency synchronous circulating pumps Wilo Stratos Para and Grundfos
Alpha 2L. the connections to the heating loop or to the distributor are made in 1”1/4 female thread.
The overpressure control is given by the self-regulating pump units which, thanks to the integrated control of the differential pressure at constant Δp or variable Δp, allow to equalize the performances and
the efficiency of M3 pump units of DN25 series even in presence of very high flows (up to 4.800 l/h).
In the diagram at side you can see the typical curves of Wilo Stratos Para 30/1-8 circulating pump in the two available working modes.


Dimensions: 250x400x170 mm (EPP insulation box)
Centre distance 125 mm

For power up to 111 kW (with Δt 20 K)
Maximum flow 4800 l/h.
Kvs value: 21.0


Approximate data calculated with a 8 m nominal lifting power circulating pump (Wilo Stratos Para 30/1-8).

Unmixed pump unit 5/4


Available circulating pumps:

Grundfos Alpha 2L 32-60 (part of the package)
Wilo Stratos Para 30/1-7
Wilo Stratos Para 30/1-8


The unit for 1”1/4 (180 mm) circulating pumps consists of:



  • Connection 5/4”.
  • Flanged ball valve with T-handle.
  • High efficiency synchronous pre-wired circulating pump (for the models that include it).
  • Flanged ball valve supplied with in-handle thermometer (coded red, range 0°C-120°C).



  • Flanged ball valve supplied with in-handle thermometer (coded blue; range 0°C-120°C).
  • Connection with 20 mbar non return valve (ball valve side).
  • Connection 5/4”.










UNI2 controller

UNI2 controller

UNI2 is a universal controller designed for heating systems equipped with:

  • Two central heating circuits with mixing valves (e.g. for heater supply and floor heating)
  • Domestic hot water (DHW) circuit
  • DHW circulation circuit

Thanks to its grapichal display the Euroster UNI2 cooling-heating controller gives precise and wide ranged information about its continous operation, making it lot easier to set and to check the device. The unit also includes anti-freeze function which prevents malfunctions outcoming of the freezing.
Furthermore the controller is useable for buffer tank and boilers, since it has an overheating protection. During overheating it overrides the signal from the room thermostatic.


Euroster UNI2 cooling-heating controller is equipped with: multifunctional double mixing valve controller,
quick to assemble set, graphical LCD display, advanced microprocessor technology, knowledge of five commander units in one and the thermal sensors.
Controller functions: mixed circles cooling-heating, two thermostat signal receptions, start two mixing valves, start domestic hot water pump, optional operating modes, start circulating pump, outer-temperature sensor, weekly programming option, launch other boiler based on room thermostat, anti-stop function, freeze prevention, overheating prevention.


UNI2 controller

The heating system controller is equipped with two separate mixing valve and pump controllers, which can be launched by room thermostat signal and tuned by outer temperature signal. Able to receive two separate thermostat signals which are voltage free. The mixing valves can be controlled to heat and cool by a weekly program.
Euroster UNI2 cooling-heating controller provides two other functions: launch domestic hot water pump of which’s operational mode is selectable (primary or secondary) even by weekly programming. Furthermore its able to launch a circulating pump which has great advantages that its launchable in two different operational modes: temperature surveillance or time definition. Both of these even by weekly programming.
+ automatic fail-safe pump control
+ floor temperation
The heating system controller is able to launch other boilers (ex.: gas boiler).

Opening dinamics:

UNI2 open dinamics

UNI2 example system:

UNI2 working

1. External temperature sensor
2. Room control unit for circuit 1
3. Temperature sensor for circuit 1
4. Central heating pump for circuit 1
5. Mixer for circuit 1
6. Supply temperature sensor
7. Room control unit for circuit 2
8. Temperature sensor for circuit 2
9. Central heating pump for circuit 2.
10. Mixer for circuit 2
11. Feed pump for DHW tank
12. Temperature sensor for DHW tank
13. DHW circulation pump
14. Temperature sensor for DHW
15. Circulation

UNI2 controller wiring:

UNI2 wiring

Back of the UNI2 controller:

UNI2 controller back

UNI2 sizes:

UNI2 sizes

Length of sensors included int he set:
1. Outdoor temperature sensor (5m)
2. Powertemperature sensor (1,5m)
3. CH1 circuit temperature sensor (1,5m)
4. CH2 circuit temperature sensor (1,5m)
5. CH3 circuit temperature sensor (1,5m)
6. Additional heat source temperature sensor (1,5m)

UNI2 technical data






2-way insulated distributor 5/4"

Distributor 2-way 5/4


Maximum flow rate up to 7,25 m³/h, 165 kW (Δt20K)
max. 6bar.
Connection for pump units: 5/4”
Connection for buffer tank: 2”
Insulation box section size: 152x152x625mm