A compact and efficient open vent gas boiler

An open vent, wall mounted gas fired condensing boiler which is compact enough to fit in a standard kitchen cupboard. Also suitable for use in other applications where there is only limited space available.

  • EfficiencyLabel
  • Designed for
  • Powered by
  • Up to
    35 kW
  • Energy efficiency
  • Ultra compact
  • Smart home
  • Standard warranty
    5 years
  • Made in
  • Rated outputs: 13 kW, 16 kW, 19 kW, 26 kW and 35 kW
  • Compact dimensions to fit in standard kitchen cupboards
  • LPG conversion available
  • Energy efficiency class: A
  • Standard efficiency up to 97% through stainless steel Inox-Radial heat exchanger
  • Exceeds ErP Directive minimum efficiency requirements
  • Weather compensation option
  • Large user display
  • 5 year comprehensive warranty as standard
  • Viessmann Trained Installers can now offer their customers an extended warranty option up to 10 years

Key Benefits

Efficient, durable, quiet

The corrosion-resistant stainless steel Inox-Radial heat exchanger with unrivalled wall thickness, is extremely durable and achieves efficiency levels of up to 97%.

The boiler's special design ensures the very low operating noise of 39 dB(A) maximum (26 kW), which is perfectly acceptable even in the kitchen.

Intelligent weather compensation

The Vitodens 100-W Open vent can even operate in weather compensated mode without incurring a costly heating system modification, all that is needed is a simple upgrade.

Weather compensation acts like an auto-pilot as it detects outside temperature changes and automatically adjusts the flow temperature of the boiler, achieving gas savings of up to 12% in the process.

Compact dimensions

With a depth of only 285 mm (340 mm on the 35 kW model) the compact Vitodens 100-W Open vent boiler is perfectly suited for integration into standard kitchen cupboards.

It can also be used in a vast number of other applications where there is only limited space available.

Smart home ready

The Vitodens 100-W has been designed and manufactured with smart homes in mind.

With our optional easy-to-install tado° thermostat and smartphone app, you can optimise your heating environment and save energy costs from the palm of your hand - no matter where you happen to be. (An extension module is also required)

Versatile system solutions

Whilst being specifically designed for open vent heating systems, the Vitodens 100-W Open vent is suitable for sealed systems using an additional expansion vessel safety valve.

The boiler also shares the various flue options available for the Combination and System models of the Vitodens 100-W gas condensing boiler range.

Efficiency Label

A decision-making aid for buying a new heating system. The ErP directive is a new, energy efficiency identification, standardised throughout Europe; making energy consumption more transparent.

Want more information about this product?

Not sure which gas boiler you need? Use our simple tool.

Product Data

tado° - Intelligent Heating Control

With the easy-to-install tado° thermostat and smartphone app, you can optimise your heating environment and save energy costs.

ViCare app

With the new ViCare app, operating your heating system has become even easier and more intuitive.

Vitotrol app

With the Vitotrol app and a smartphone, controlling Viessmann heating systems couldn't be easier.

Brochure | Domestic Gas Boiler Guide

Weather compensation


Vitodens 100-W Open Vent

Vitodens 100-W Open Vent

Output (kW)

Vitodens 100-W Open Vent

7.9 to 35 kW

Standard seasonal efficiency [SEDBUK 2009/2012]

Vitodens 100-W Open Vent

97 % (Hs) [gross cv] / 108 % (Hi) [net cv]


Vitodens 100-W Open Vent

Natural Gas & LPG

Application range

Vitodens 100-W Open Vent

Residential buildings, commercial enterprises, local authority premises, new builds and modernisation projects


Vitodens 100-W Open Vent

Easy to use dials with a large LCD display

Heat Only boiler

Vitodens 100-W Open Vent

With 5 outputs 13, 16, 19, 26 & 35 kW

Additional features

Vitodens 100-W Open Vent

MatriX cylinder burner and Inox-Radial heat exchanger

Energy efficiency class

Vitodens 100-W Open Vent


Application range

Vitodens 100-W Open Vent

Detached and two-family house, apartment buildings, new build and modernisation projects

Like what you see? Get a quote from a local installer.

Related Products

Vitodens 050-W
A compact, low-cost gas condensing boiler    

With compact dimensions, low weight and quiet operation, the attractively priced Vitodens 050-W gas condensing boiler will integrate effortlessly into any living space. Which? Best Buy, Vitodens 050-W 29 kW Combi.

Discover the Vitodens 050-W
  • Up to 10 years
  • Easy control with
    LCD Display
  • Smart Home
     with tado°
  • Boiler Plus
Discover the Vitodens 050-W
  • EfficiencyLabel
  • EfficiencyLabel
Trending topics
Latest Topics