Key Features

• Output: 15–21kW
• Flue options: C/F, low/ high/ vertical B/F
• C/F size: 100 mm
• ErP rating: A
• Dimensions: 865(H) x 602(D) x 413(W) mm
• Flow connection: 28mm
• Return connection: 22mm
• Service access: Front
• Warranty: 2 years
• Riello low NOx technology
• White casing
• Unique 'Easy-Fit' balanced flue system - 1 flue fits all boilers
• Riello low NOx technology
• Patented stainless steel heat exchanger

What's Included

• Warmflow Agentis 15-21kW System Oil Boiler - I21S
• Factory-fitted Grundfos UPM3 FLEX AS circulating pump
• Factory-fitted 3 bar safety valve
• Factory-fitted automatic air vent
• 12l Expansion vessel

Warmflow Agentis 15-21kW System Oil Boiler - I21S Overview

The Warmflow Agentis 15-21kW System Oil Boiler - I21S features Warmflow's unique patented heat exchanger and Riello Low NOx technology for seamless integration and quiet operation for heat and hot water within any indoor application.

Slimline Design and Extras

This internal oil boiler features a slim design to fit into kitchen and utility rooms and as well as a Unique 'Easy-Fit' balanced flue system with multiple options available, a white casing and an A ErP rating. 

It also comes equipped with a factory fitted Grundfos UPM3 FLEX AS circulating pump, a factory-fitted 3 bar safety valve, a factory-fitted automatic air vent and a 12l expansion vessel.