2-way pump unit with electronic circulating pump. Integrated climatic controller Clima 4

2-way pump unit with 3-way mixing valve and electronic circulating pump. Integrated climatic controller for one mixed and direct heating circuit

Pump unit with climatic controller for two heating circuits: mixed and direct; control of contact with bolier (heat source) for its starting and turning off. The unit, by acquiring the outside temperature, sets the correct supply temperature for both circuits, mixed and direct, on the basis of the set up climatic curves. The unit is supplied completely assembled and tested. No wiring operations are needed: the circulating pump, the actuator for mixing valve and the climatic controller are pre-wired for a pratical and effective installation.


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



  • Connection.
  • Isolating flanged ball valve with unions.
  • 3-way mixing valve with 3 points servomotor.
  • Electronic circulating pump, OEM version, Wilo Stratos-PICO 25/1-6, A class.
  • Flanged ball valve supplied with in-handle thermometer (coded red, range 0°C-120°C).



  • Flanged ball valve with non return valve 20 mbar (which can be excluded by rotating the handle by 45°) supplied with in-handle thermometer (coded blue; 0°C-120°C).
  • “T” connection for mixing valve.
  • Isolating flanged ball valve with unions.
  • Connection.


Centre distance 125 mm. EPP insulation box (Measurements: 250x466x215 mm).

A special back plate fixes the unit to the insulation box and it allows a quick fitting to the wall or to the solar cylinder.


PN 10. Max Temperature 110°C.

(max. 40°C ambient temperature and 90°C fluid temperature).

External connections: 1” Female.



For power up to 35 kW (with ∆t 20 K) and maximum flow 1500 l/h.

Kvs Value: 6,0.

Approximate data calculated with a 6 m nominal lifting power circulating pump.

For an accurate measuring or higher flow, please refer to the curves of the circulating pumps (constant ∆p and variable ∆p).


    ENERGETIC CLASS: A high energetic class circulating pump like, for exemple, the model

    Wilo Stratos PICO 25/1-6 (A Class) installed in the CLIMA units, allows an energy saving as

    much high as its energetic class. Each class step corresponds to a 20% energy saving. In

    accordance to the EUP european regulation, starting from 2013, the use of A Class High

    Efficicency circulating pump, will be compulsory. 





3-way mixing valve with actuator and bidirectional turning angle of 90 °; led activities at the opening and closing. Switch for manual operation through the dial indicator. A special connector allows to replace the actuator in the event of breakdown or malfunction without intervening on the electrical wiring.

Kvs of mixing valve: 10.0




  Wilo Stratos PICO OEM 25/1-6. A class high efficiency circulating pump with electronically

  commutated motor. Integrated differential pressure control: constant Δp or variable Δp.

  •  Costant ∆p: for heating circuits with a stable pressure drop (i.g. underfloor heating) or plants where  the pressure drop of pipes is negligible in comparison with the pressure drop of the thermostatic radiator valves, or where indipendently from open thermostatic radiator valves,same differential pressure is requested.

  •  Variable ∆p: in order to achieve the max energy saving and noise reduction. It is recommended in plants where the pressure drop of the pipes is higher than the pressure drops of the regulating valves, or more simply, when the requested differential pressure is decreasing when the flow comes down.

   In compliance with European Directive EUP 2013/2015. Low energy   consumption from

  3 W to 40 W at max flow. Automatic air vent program. Which allows a quick elimination of air

  during the first start of the plant. Molex automatic connector, which allows to replace the

  circulating pump in case of failure or bad working, without having to operate on electric wires.



        Costant ∆p                                                Variable ∆p






Climatic controller with wide LCD display to manage two heating circuits: mixed and direct..


  • Pictogram of mixed circuit with evidence of status of activity of relays: circulating pump and mixing valve in opening or closing position; circulating pump of direct circuit and request of heat source.
  • Visualization of temperature of sensors: outside sensor, supply sensor, calculated supply sensor and room sensor (optional). Active modality of working: day or night.
  • Separate pre-setting of the two characteristic curves (one for each circuit) with linear slope or broken and related day-night correctors..
  • Protection function: anti-blockage circulating pump, anti-frost control, min and max supply temperature.
  • Daily up to three time bands can be set up (for each circuit): active heating circuits in day modality or reduction night
  • Data memory with statistical analisys of the working of the plant (temperatures, working times, error messages, etc).
  • Optional RC21 for remote control of mixed circuit, with activable thermostat function.


The controller is supplied pre-wired with following sensors (PT1000):


  • power cable with Schuko plug;
  • cable for controlling circulating pump with Molex connector;
  • cable for controlling servomotor with automatic connector PR120;
  • temperature sensor for mixed circuit TR/S1,5;
  • cable with outside “sensor box” to connect outside temperature sensor TA/52 and remote control RC21 (optional);
  • outside temperature sensor TA52.
  • dip sensor TT/P4 for buffer or hydraulic switcher.



Mixed cirquit                                                       Mixed circuit + boiler



Mixed and direct circuit + boiler                          Mixed circuit + contribution boiler



 Mixed circuit + direct circuit                         Mixed and direct circuit + contribution boile







For a fast and easy connection of the temperature sensors you do not have to handle the controller, it is enough to plug the cables in the automatic connectors of the sensor box.




Code 1": 20359R-M3-HC4-P6
Models type M33 are available with built-in by-pass in mixing valve for underfloor heating plants:
Code 1”: 20359R-M33-HC4P6


  • Model: Clima 4