Wilo-Star-RS | Wilo
Your advantages

Your advantages

  • Suitable for any installation location with a horizontal shaft; terminal box in 3-6-9-12 o'clock position
  • Three preselectable speed stages for load adjustment
  • Easy and safe installation due to practical wrench attachment point on pump body
  • Simplified electrical installation due to terminal box with removable threaded cable connection that can be used on both sides; quick connection with spring clips
Series description


Glandless circulator with threaded connection. Preselectable speed stages for power adjustment


Hot-water heating systems of all kinds, industrial circulation systems, cold water systems and air-conditioning systems


Operating modes

  • Speed-stage switching

Manual functions

  • Setting of speed stages (3 speed stages)


  • Wrench attachment point on pump body
  • Cable lead-in possible on both sides
  • Quick connection with spring clips
  • Blocking current-proof motor



Wilo-Star-RS 25/4


Standard pump (screw-end pump)


Nominal connection diameter Rp


Nominal delivery head [m] at Q = 0 m3/ h

Technical data

  • Permissible temperature range -10°C to +110°C
  • Mains connection 1~230 V, 50 Hz
  • Protection class IP 44
  • Threaded connection Rp ½, Rp 1 or Rp 1¼
  • Max. operating pressure 10 bar


  • Pump housing: Grey cast iron
  • Impeller: Plastic
  • Shaft: stainless steel
  • Bearing: Carbon, metal impregnated

Delivery state

  • Pump
  • Gaskets
  • Installation and operating instructions

Installation and operating instructions

Wilo-Star RS, RSD

Article Number 4185968
Edition 1503
Page format 105.1 x 148.2 mm
Number of pages 136
PDF (5 MB)

General overview (Documents)

General overview 2019 International version

Article Number 2200591
Edition 2018
Page format 209.9 x 297.0 mm
Number of pages 74
PDF (40 MB)

General overview 2021 International version

Edition 2020
Page format 209.9 x 297.0 mm
Number of pages 74
PDF (10 MB)

Certificate REACH (Documents)

REACH regulation

Edition 2021-10
Page format 209.9 x 297.0 mm
Number of pages 2
PDF (162 KB)