Oil condensing boilers use the latest heating technology

Oil heating systems are still among the most widely used heating systems. No wonder, because the fuel is energy-rich and the system is considered safe. If homeowners decide to buy a Viessmann condensing boiler for oil, they are also making an active contribution to conserving resources and saving energy. Because with an unbeatably high efficiency, up to 98 percent of the heating oil used is converted into heat.

Viessmann oil condensing boilers also have the future already built in. Because ex works, they are prepared for a changeover from exclusively fossil oil to heating oil with a proportion of bio-oil and can thus also be operated with renewable energy sources. In this way, every operator of an oil heating system with an oil condensing boiler makes an active contribution to climate and environmental protection. Viessmann has the right oil condensing boiler for every heating requirement.


The picture shows an oil condensing boiler with hot water tank underneath

Save up to 35 percent energy with a modern oil condensing boiler

Older boilers generally operate inefficiently and often consume much more fuel than necessary. In Germany alone, there are still around two million heating systems in operation that are more than 25 years old. By promptly replacing a technically outdated heating system with a highly efficient oil-fired heating system with condensing boiler technology and in combination with solar technology, end consumers could save up to 35 percent energy. In arithmetical terms, this would be ten percent of Germany's total energy consumption while reducing CO₂ emissions by 54 million tons a year.

Combining the new oil condensing boiler with solar collectors

The free energy of the sun for heating support and domestic hot water is still too little used. Yet solar technology is more than mature and has become very cost-effective in recent years. In addition, the acquisition is supported by the state with high subsidies. Today, every new oil condensing boiler should also be combined with solar collectors to use free solar energy, especially since Viessmann oil condensing boilers are already designed to use solar energy.

When operating an oil condensing boiler in conjunction with Vitosol solar collectors for central heating backup, the requirements of the EEWärmeG and EWärmeG (Baden-Württemberg) are met. The building owner can apply for public subsidies for this investment. Current information on this can be found in our subsidy database. Further information on the subject of financial incentives and government subsidy programs can also be found in the section on subsidies for oil condensing technology.

Vitoset heating oil tanks for your new oil condensing heating system

The complete system of a condensing oil heating system also includes economical, space-saving and trouble-free heating oil storage. For new builds, extensions or renovations, a heating oil tank from the Vitoset range for your oil condensing boiler is a safe solution in any case - in detached houses or apartment buildings as well as for residential complexes or commercial buildings.

Operating the new condensing boiler for oil via the Internet using an app

With the free ViCare app, you can then conveniently control your new oil condensing boiler online via app - even from your vacation spot or workplace. All you need for this digital operating convenience is the Vitoconnect internet interface, which your heating engineer can set up on request during the new installation.

How the oil heating with condensing technology works

When fuel oil is burned, hot exhaust gases are produced in addition to heat. In older boilers, these gases are discharged through the chimney into the open air. This is necessary for two reasons. On the one hand, some components of the exhaust gases are very acidic and can damage the system itself as well as the exhaust pipes in the long term. On the other hand, the exhaust gases must not be allowed to condense, otherwise they would become too heavy and could no longer escape from the chimney. This design-related process means that the heat hidden in the exhaust gases remains unused.

Compared to older condensing boilers, Viessmann condensing boilers for oil make additional use of this latent "condensation heat". This is released when the exhaust gases cool down and the resulting hot water vapor condenses. In this way, up to 98 percent of the energy content in the heating oil is converted into heat. Detailed descriptions of this process can also be found in the section How oil condensing technology works.

To activate the video please click on the play button. Please note that by calling up the video, data is transmitted to YouTube. For details please refer to our privacy policy.

How does oil heating with condensing technology work?
In the video: How does condensing technology work?

The picture shows a heat exchanger, which is essential for the oil condensing boiler.

Oil condensing boiler with Inox-Radial heat exchanger

Oil heating is an environmentally friendly and economical heating technology that can be used to save energy efficiently. All Viessmann oil condensing boilers are equipped with the Inox-Radial heat exchanger made of stainless steel. This indestructible technology stands for the high efficiency of 98 percent and is characterized by a long service life and safe and efficient operation. Find the right oil condensing boiler for you and your heating needs from this overview.

Moderne Ölheizung - So funktioniert Brennwerttechnik

Modern gas heating - resource efficiency with condensing technology

Condensing technology not only utilises the heat generated by combustion as a measurable temperature of the hot gases (net calorific value), but also the water vapour content (gross calorific value). Condensing boilers are able to extract almost all of the heat contained in the flue gases and to convert it into heating energy.

Condensing boilers use high performance heat exchangers. These cool the flue gases before they escape through the chimney, to the extent that the water vapour contained in these gases is deliberately condensed. This releases additional heat which is transferred into the heating system.

With this technology, a gas condensing boiler achieves a standard seasonal efficiency [to DIN] of up to 98 % (relative to Hs). Condensing boilers are therefore particularly energy efficient, looking after both your wallet and the environment.

Calorific value (Hs)

The gross calorific value (Hs) defines the amount of heat released by complete combustion including the evaporation heat latent in the water vapour of the hot gases.


Heating with oil

By using a Viessmann condensing boiler to convert fuel oil into heat, you are making an active contribution towards using resources efficiently and saving energy, thanks to the boiler's unbeatably high efficiency of 98 percent (relative to the gross calorific value (Hs)).

Our oil condensing boilers come with the future built in. They are designed to accommodate a changeover from fossil oil to fuel oil mixed with a certain percentage of bio-oil, which means that they can be run partially on renewables.