Return temperature unit, Thermostatic mixing function


  • Thermostatic constant temperature control
  • Available with fixed or adjustable temperature setting
  • High class insulation shell
  • High efficiency circulation pump
The ESBE series GST100 is a return temperature unit designed for applications, where a return temperature control is required. Equipped with two shut-off valves with thermometers, check valve, high class insulation shell and high efficiency circulation pump. The GST100 is delivered with a 3-way thermostatic mixing valve, which comes in two versions: fixed temperature or adjustable temperature setting.
Product range

GST130, Fixed temperature setting

GST131, GST141
GST132, GST142 Reference DN Pump Temperature range [°C] Connection I Connection J Weight [kg] Note
61120100 GST131 25 Wilo 25/6 50/55/60 G 1" G 1½" 5,0 The Return Temperature Units Series GST130 are delivered with three wax elements: 50/55/60ºC. Factory assembly: 55ºC.

GST140, Adjustable temperature setting

GST131, GST141
GST132, GST142 Reference DN Pump Temperature range [°C] Connection I Connection J Weight [kg]
61120200 GST141 25 Wilo 25/6 50–75 G 1" G 1½" 5,4
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: <0,20
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.: +100 °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, Iron, Steel
Sealing materials: PTFE, Aramid fibre, EPDM

Integrated pump

Wilo Yonos Para 25/6-130 RKA
Power supply 230 ± 10% V AC, 50/60 Hz
Power consumption 3 — 45 W
Enclosure rating IP X4D
Insulation class F
EEI (Energy Efficiency Index), circulation pump <0,20

Integrated valve

ESBE VTC317, DN20-3,2 55°C
max. Differential pressure drop 100kPa (1bar)
Opening temperature 55 ± 2°C
Leakrate in % of flow A-AB: Tight;
B-AB: max. 3% of Kvs
Rangeability Kv/Kv min, A-AB 100
LVD 2014/35/EU
EMC 2014/30/EU
RoHS3 2015/863/EU
PED 2014/68/EU, article 4.3
ErP 2015
EnEV 2014


Dimensioning guide - Please see data sheet


Please see the Installation instruction
Accessories and Spare Parts

Spare parts

Art No. Reference Designation Note Instruction manual
67000600 67000600 GSP903 ESBE GSP903 Thermometer upgrade set, 2 pcs/package download
57000200 57000200 VTC931 ESBE VTC931 Thermostat, 55°C download
57000300 57000300 VTC931 ESBE VTC931 Thermostat, 60°C Load valve VTC317 download
67000100 67000100 GSP901 ESBE GSP901 Pump RKA 25/6 Wilo DN25 download
67000300 67000300 GSP901 ESBE GSP901 Pump RKA 25/7.5 Wilo DN32 download
67000400 67000400 GSP901 ESBE GSP901 Pump UPM3 25-50 Grundfos DN25 download
67000500 67000500 GSP907 ESBE GSP907 Pump Grundfos Hybrid UPM3 25-70 DN25-DN32 download
Download area

Download area

Type Preview Download
Data sheet GST100 download
Installation instruction GST100 (de, en, fr, it, pl, sv) download
Installation instruction Wax element GST131 download
Installation instruction GST100, Wilo Pump download
Certificate Declaration of Conformity, GST100 download
Certificate Declaration of Conformity UK CA, GST100 download
Certificate Building Product Declaration BPD3, GST100 download
Certificate EAC certificate (RU) download
Certificate UKRSEPRO certificate (UA) download
Image GST131, high res download
Image GST141, high res download
2D Image GST131, GST141 download
3D drawing (stp file) GST131, DN25 download
3D drawing (stp file) GST141, DN25 download