Circulation unit, direct supply


  • High efficiency circulation pump
  • High class insulation shell
  • Pre tested and ready to use
  • Compact design
The ESBE series GDA300 is a direct supply circulation unit designed for applications, where the energy transport in the most efficient way is required. Equipped with two shut-off valves with thermometers, check valve, high class insulation shell and high efficiency circulation pump. You can be sure that ESBE delivers the best circulation unit for both your economy as well as for the environment. It is simply the most efficient direct supply unit available. When designing the circulation unit product line the focus at ESBE has been to simplify installation. This goes through the whole product from pre assembly, mounting brackets and insulation to packaging design.
Product range

GDA311 Reference DN Pump Connection I Connection J Weight [kg] Note
61003100 GDA311 20 Wilo RSTG 15/7,5 G ¾" G 1" 3,7
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
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
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 GDA300 download
Installation instruction GDA300 (en, pl, ru, sv) download
Installation instruction GDA300 (de, en, es, fr, it, nl) download
Certificate Declaration of Conformity, GDA300 download
Certificate Declaration of Conformity UK CA, GDA300 download
Certificate Building Product Declaration BPD3, GDA300 download
Certificate EAC certificate (RU) download
Certificate UKRSEPRO certificate (UA) download
Image GDA311, high res download
2D Image GDA311 download
3D drawing (stp file) GDA311, DN20 download