Wilo-Star-ZD | Wilo
Your advantages

Your advantages

  • Twin-head pump for single or parallel operation
  • Suitable for every installation position with horizontal shaft; terminal box in 3-6-9-12 o'clock position
  • Internal bypass circulation, which prevents Legionella growth in the standby unit
  • Increased reliability in individual operation due to the constant availability of a standby unit ready for operation
Series description


Glandless twin-head circulator with screwed connection; preselectable speed stages for power adjustment


Domestic hot water circulation systems in the industry and building services.


Operating modes

  • Speed-stage switching

Manual functions

  • Setting the speed stages (3 speed stages)


  • Double switchover valve in pump housing
  • Cable inlet in possible on both sides
  • Internal bypass
  • Quick connection with spring clips
  • Blocking-current proof motor



Wilo-Star-ZD 25/6


Twin-head circulator for domestic hot water


Nominal connection diameter


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

Technical data

  • Fluid temperature
    • Drinking water up to 3.21 mmol/l (18 °dH): max. +65 °C, in short-time duty (2 h) up to +70 °C
  • Mains connection 1~230 V, 50 Hz
  • Protection class IP44
  • Nominal diameter Rp 1
  • Max. operating pressure 10 bar


  • Pump housing: Bronze
  • Impeller: Plastic
  • Shaft: Ceramic
  • Bearing: Carbon, synthetic resin-impregnated

Delivery state

  • Pump
  • Gaskets
  • Installation and operating instructions

Installation and operating instructions


Article Number 4236978
Edition 2019-08
Page format 105.1 x 148.2 mm
Number of pages 184
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

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

Certificate REACH (Documents)

REACH regulation

Edition 2020-08
Page format 209.9 x 297.0 mm
Number of pages 2
PDF (158 KB)
Product list
Product descriptionPump connectionPort-to-port length L0Maximum operating pressure PNMains connectionGross weight, approx. mPieces per palletArticle number