Wilo Star S 21 FX, 115V, 3-Speed Cast Iron Star Series Circulator


Wilo Star S 21 FX, 3-Speed, 90 degrees rotated flanges, Cast Iron Star Series Circulator for hydronic radiant floor

The Wilo Star S 21 FX Circulator Pump is the perfect companion for your heating and cooling needs. Powered by 115V and equipped with a 3-speed feature, it provides optimal performance. The robust cast iron build ensures long-lasting durability

Technical sheet User manual


Part #: 4090765 SKU: WIL-S21-FX Categories: , GTIN: 4016322779384 MPN: 4090765

Wilo Star S 21 FX circulator pump incorporates a cast iron housing, three speed motor (Low/Med/High).  Wilo Star S 21 FX is among the most popular and most versatile circulator pump models on the market. Pump’s performance parameters cover nearly all traditional heating applications – from radiant and baseboards, to fan coils and zoning and many others. 3 speeds allow to set up the circulator pump in a way, that matches the system’s requirements, while wet rotor design allows it to be virtually silent while operating.


  • 115V/60Hz
  • 90 degrees rotated flanges
  • Built-in motor protection for longer life and better performance.
  • Suitable for a wide range of applications, including radiant heating, hydronic heating, fan coil heating,
  • solar and other system types.
  • Whisper-quiet operation for sound sensitive installations.
  • Includes (2) Gaskets (O-rings).
  • UL/CSA listed.


  • Closed loop radiant heating & snow melting systems.
  • Baseboard/Radiator/Fan coil heating and other hydronic heating applications.
Weight3,5 kg
Dimensions15 × 19 × 17 cm

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