Circulation unit, Mixing function


  • Outstanding flow control thanks to the progressive characteristic of the valve
  • Ready to use with most controllers available on the market
  • High class insulation shell
  • Compact design
  • "Quick fit" connection between Valve and Actuator

The ESBE series GRA300 is a circulation mixing unit which is intended for heating circulations where the outstanding flow and temperature control are required. Equipped with two shut-off valves with thermometers, check valve, high class insulation shell and high efficiency circulation pump. This compact unit is equipped with 3-way rotary progressive mixing valve and actuator. 

The Circulation Mixing Unit ensures best regulation performances independent from flow rate and low oversizing risk thanks to progressive valve characteristic, as well as the working possibility with most controllers available on the market.

Product range

GRA311 Reference DN Pump Connection I Connection J Weight [kg] Note
61043100 GRA311 20 Wilo 15/7,5 G ¾" G 1" 4,5
Installation support

Installation examples

Installation examples


Technical data

Technical data

Pressure class: PN 6
Working pressure: 0,6 MPa
Insulation: EPP λ 0,036 W/mK
EEI (Energy Efficiency Index), circulation pump: <0,21
Media, Heating water: in accordance with VDI2035
Media, Water/Glycol mixtures: max. 50 % (above 20% admixture, the pump data must be checked)
Media, Water/Ethanol mixtures: max. 28 %
Media temperature, max.: +110 °C
Media temperature, min.: 0 °C
Ambient temperature, max.: +50 °C
Ambient temperature, min.: 0 °C
Connections, Internal thread (G): ISO 228/1
Connections, External thread (G): ISO 228/1
Material, in contact with water Components: Brass, Cast iron, Steel
Sealing materials: PTFE, Aramid fibre, EPDM

Integrated pump

Wilo RSTG 15/7,5
Power supply 230 ± 10% V AC, 50/60 Hz
Power consumption 4 — 75 W
Enclosure rating IP X4D
Insulation class F
EEI (Energy Efficiency Index), circulation pump <0,21

Integrated valve

ESBE VRG438, DN20-8 QF
Pressure class PN10
Kvs 8
max. Differential pressure drop 100 kPa (1 bar)
Close off pressure 200 kPa (2 bar)
Leakrate in % of flow <0,05%*
* Differential pressure 100 kPa (1 bar)

Integrated Actuator

ESBE ARA661 Quick Fit
Control signal 3-point SPDT
Power supply 230 ± 10% V AC, 50Hz
Power consumption 5 VA
Running time 90° 120 s
Enclosure rating IP41
Protection class II
LVD 2014/35/EU
EMC 2014/30/EU
RoHS3 2015/863/EU
PED 2014/68/EU, article 4.3


Dimensioning guide - Please see data sheet


Please see the Installation instruction
Accessories and Spare Parts

Spare parts

Art No. Reference Designation Note Data sheet Instruction manual
67003500 67003500 GSP933 ESBE GSP933 Ball valve DN 20 DN20 download download
67000600 67000600 GSP903 ESBE GSP903 Thermometer upgrade set, 2 pcs/package download download
67003300 67003300 GSP933 ESBE GSP933 Ball valves incl thermometer DN20 G¾", 2 pcs/package DN20, G¾" download download
67003800 67003800 GSP933 ESBE GSP933 Ball valves incl thermometer DN20 G1", 2 pcs/package DN20, G1" download download
67003000 67003000 GSP930 ESBE GSP930 Insulation circulation unit DN 20 download download
67006100 67006100 GSP961 ESBE GSP961 Actuator ARA661 120s 230V 3p QF download download
67000700 67000700 GSP912 ESBE GSP912 Adaptor kit VRG&ARA Adaptor kit for ESBE valves series VRG and Actuators series ARA. DN20-DN32 download download
67003100 67003100 GSP931 ESBE GSP931 Pump RSTG 15/7,5 Wilo download download
67003900 67003900 GSP932 ESBE GSP932 PWM cable Wilo RSTG, 3m download download


Art No. Reference Designation Note Data sheet Instruction manual
66000600 66000600 GMA331 ESBE GMA331 Manifold for 3 circulation units, without integrated hydraulic separator function. DN20 download download
66000500 66000500 GMA321 ESBE GMA321 Manifold for 2 circulation units, without integrated hydraulic separator function. DN20 download download
Download area

Download area

Type Preview Download
Data sheet GRA300 download
Installation instruction GRA300 (en, pl, ru, sv) download
Installation instruction GRA300 (de, en, es, fr, it, nl) download
Certificate Declaration of Conformity, GRA300 download
Certificate Declaration of Conformity UK CA, GRA300 download
Certificate Building Product Declaration BPD3, GRA300 download
Certificate EAC certificate (RU) download
Certificate UKRSEPRO certificate (UA) download
Image GRA311, high res download
2D Image GRA311 download
3D drawing (stp file) GRA311, DN20 download