Gas heating guide

What are the benefits of modernization? How much energy costs can be saved with a new gas heating system? What does the upcoming gas conversion mean? Isn't gas a finite fuel and how can I make myself independent of its price development? The five most frequently asked questions about gas heating and their answers.

Why should you upgrade your old gas heating system to condensing technology?

Of the approximately 13 million gas boilers in this country, around two thirds operate with calorific value technology. According to the Federal Association of the German Heating Industry (BDH), that's just under nine million appliances for which the full potential is far from exhausted. This is because, unlike gas heating with condensing technology, a calorific value appliance such as the low-temperature gas boiler only converts a maximum of 83 percent of the energy contained in the fuel into heat. The rest is lost unused as hot exhaust gases.

If, on the other hand, homeowners and modernizers rely on condensing technology, the fuel is converted into heat with virtually no losses. This is possible because the technology causes the hot exhaust gases to condense so that it releases the hidden heat. The additional use of this heat increases the efficiency of a gas condensing boiler to up to 98 degrees. This in turn means lower heating costs, as less fuel needs to be burned for the same heat output. At the same time, this efficiency helps to reduce the burden on the environment and conserve natural gas, a fossil fuel. What else speaks in favor of using condensing technology is summarized in the section Advantages of gas boilers.

How much energy costs can be saved with a new gas heating system?

15, 30, 50 percent: When it comes to the question of how much heating cost savings homeowners can expect with heating modernization, some providers quote partly unrealistic figures. This question can only be answered if the initial situation is clearly defined. One of the most important points concerns the boiler to be replaced. If it uses calorific value technology, savings of 15 percent are realistic. If the old boiler is a constant-temperature boiler, 30 percent is also possible.

If, in the course of modernizing the heating system, homeowners also opt for a combination of gas condensing boiler and solar thermal system, they can save up to 35 percent. It is important here that the complete system, which includes not only the boiler but also the radiators, the pump, the pipe system, etc., is matched to each other. In addition to the cost savings, the use of condensing technology has another advantage: CO2 emissions are also reduced with the use of gas condensing technology.

Is the existing heating system approved for all types of gas? Are additional costs to be expected for a gas conversion?

In the coming years, many gas boilers will have to be technically converted during the gas switchover in western Germany. The gas conversion serves both to guarantee supply and to standardize the type of gas. Specifically, L-gas will be converted to the more energy-rich H-gas. Those who already own a Viessmann gas condensing boiler with the Lambda Pro Control intelligent control system will not be affected by the changeover. This is because the control system automatically adapts to the new gas quality and can burn the H-gas without any problems.

Anyone who does not own a gas condensing boiler with the intelligent Lambda Pro Control from Viessmann should observe all letters, instructions and deadlines that they have received from their energy supplier. No end user will have to pay for the costs incurred during the conversion. 

The gas heating guide shows schematically how power to gas works.

Is gas as a fuel also available in the long term?

Gas is a fossil fuel. This means that it is only available in finite quantities. According to calculations by many companies and governments, however, reserves will last for the next four or five decades - provided consumption does not increase dramatically.

However, this projection does not include new technologies such as power-to-gas and deposits that are not yet operating economically. Many experts see the former in particular as an opportunity to achieve the energy turnaround and thus the climate targets after all. Power-to-gas describes the conversion process of renewable electricity (e.g., photovoltaic or wind power) into storable, artificial natural gas. The already well-developed German gas distribution network can be optimally used for the distribution of this heat.

How can independence from gas prices be achieved?

Even though the price of gas has been relatively low for years, a price increase cannot be ruled out. Those who opt for tomorrow's technology today are not only making themselves independent of their fuel supplier to a certain extent. In the long term, it will reduce heating costs and also protect nature. Such technology is available today, for example, in the form of solar thermal energy with gas condensing boilers. In this bivalent operation, the solar system takes over the water heating completely and can also support the heating system. In this way, the gas boiler only has to do significantly less work.

Another combination consists of a gas condensing boiler and a heat pump. For long periods of the year, the heat pump takes over the hot water preparation and the heating of the rooms cleanly, efficiently and cost-effectively. The gas condensing boiler is only switched on during peak loads. A fuel cell heating system such as the Vitovalor 300-P functions similarly to this combination. It also comes with a peak load boiler that is only switched on when required. The majority of the heat and electricity demand is covered by the fuel cell unit itself. These hybrid solutions make system owners more independent of the type of energy and the energy costs.