Warmflow Agentis Internal System Boiler

I21 S / I26 S / I33 S

  • Riello low NOx technology
  • Factory fitted Grundfos UPM3 FLEX AS circulating pump
  • 12l Expansion vessel
  • Factory fitted automatic air vent
  • Factory fitted 3 bar safety valve


Warmflow has an outstanding selection of high efficiency, internal and external oil-fired boilers – including the UK & Ireland’s only AAA-rated oil boiler – you can also save both installation time and money with their new Professional range of oil boilers which comes with over £250 worth of factory fitted accessories as standard including an Adey Magnacelan Pro 2, Teddington fire valve and Crosland oil filter and much more!

Additional information

I21 S

Output 15-21kW, Height 865mm, Depth 602mm, Width 413mm

I26 S

Output 21-27kW, Height 865mm, Depth 602mm, Width 413mm

I33 S

Output 27-33kW, Height 865mm, Depth 602mm, Width 413mm