2-Way pump unit with 3-way mixing valve M2 MIX3

2-Way pump unit with 3-way mixing valve M2 MIX3


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



  • Connection.
  • 3-way mixing valve.
  • Circulating pump with press-cable (for the models with it).
  • 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.
  • Connection.


Centre distance 125 mm. EPP insulation box (Measurements: 250x380x190 mm).

PN 10. Max Temperature 110°C.

External connections: 1” or 1”1/4 Female.



For power up to 35 kW (with Δt 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 for higher flows, please refer to the curves shown in the technical section.


Available circulating pumps:


Wilo Star RS 25/6 (W6)

Grundfos UPSO 25-65 (G60)

Wilo Star RSG 25/8 (RSG8)*


Available circulating pumps for models with servomotor:


Wilo Star RS 25/6 (W6)

Grundfos UPSO 25-65 (G6)

Wilo Star RSG 25/8 (G8)*

We suggest you to install two isolating valves Art. 552 (see Correlated Articles) before the pump unit to allow an easy service or replacement of the components of the unit.



     Servomotor M21: 3 points servomotor for mixing valve. Bidirectional, reversible with fixed limit switches

      for an operating range of 90°. 

       230V, 2 min., torque: 5 Nm. IP42.

                                Several models available: see the section “Servomotors”. 



     CMP25-2 climatic controller: “touch screen” climatic controller with servomotor for mixing valve, 3 points. Bidirectional,

     reversible with fixed limit switches for an operating range of 90°. 230V, 2 min., torque: 10 Nm. IP42.



Versions available with reduced Kvs (using the special kits, see Correlated Articles). In the table below the resulting Kvs of the unit is shown, with the relevant maximum values of power and flowrate:


Mixing valve Kvs Pump unit Kvs Power Flow rate
10,0 (Standart) 6,0 (standart) 35kW 1500l/h
6,3 5 29kW 1250l/h
4 3,5 20kW 850l/h
2,5 2,4 14kW 600l/h



M2 MIX3:

Code 1”: 20355(R/L)-M3 - with circ. pump: 20355(R/L)-M3-(W6/G60/RSG8)

Code 1”1/4: 20455(R/L)-M3 - with circ. pump: 20455(R/L)-M3-(W6/G60/RSG8)


M2 MIX3 with built-in M21 servomotor:

Code 1”: 20355(R/L)-M3-M21 - with circ. pump: 20355(R/L)-M3-(W6/G6/G8)-M21

Code 1”1/4: 20455(R/L)-M3-M21 - with circ. pump: 20455(R/L)-M3-(W6/G6/G8)-M21


M2 MIX3 with built-in CMP25-2 climatic controller:

Code 1”: 20355(R/L)-M3-CMP - with circ. pump: 20355(R/L)-M3-(W6/G6/G8)-CMP

Code 1”1/4: 20455(R/L)-M3-CMP - with circ. pump: 20455(R/L)-M3-(W6/G6/G8)-CMP


“R” Codes: pump units with right supply. f.i. 20355R-M3; “L”Codes: pump units with left supply. f.i. 20355L-M3.

(*) The pump units with circulating pump Wilo RSG 25/8 (RSG8/G8) are not reversible. They are available only with right supply way.

  • Model: M2 MIX3