Are you seeking to renovate your old heating system or install a new one in your home? Then a gas heating system is well worth considering.

When you choose a gas heating system, you're going with a proven technology of the future. In many cases, gas is more efficient than other fossil fuels. Gas heating systems offer many benefits, especially if you already have access to the gas mains.

Familie am Entspannen
19.3 million gas heating systems supply heat in German homes.

Gas central heating is the most widely used type of heating system in Germany. It affordably combines advanced technology with high efficiency. Another benefit to note is that gas heating systems are ideal in combination with solar thermal systems and can also be installed easily when modernising older buildings.

  • Benefits

    • Highly efficient fuel utilisation by condensing technology.
    • The heating systems are compact and save space.
    • With no need for a fuel storage room, they offer substantial space savings, especially in new build and larger modernisation projects.
    • Advanced gas technology can also be used without a natural gas supply. In this case, the solution is liquefied petroleum gas, or LPG.
    • Such systems can qualify for subsidies, thereby reducing your investment outlay.
    • Easy to combine with solar thermal systems.
    • Good price/performance ratio, especially in modernisation projects.
  • Drawbacks

    • Gas is generally an imported fuel.
    • Gas prices are expected to rise in the long term.
    • Natural gas is a finite resource.
    • It cannot be purchased in advance to take advantage of low prices – unless a large LPG tank is available.


Since the 1990s, condensing boilers have been regarded as the "gold standard" for energy efficiency.

In principle, this technology is quite easily explained: the heat latent in flue gas is recycled. This heat recovery has a clear benefit for consumers in that the appliances utilise gas as a fuel to the optimum degree. This can be seen in the flue gas temperatures, as older low temperature appliances are known to have generated flue gases as hot as 160–200 °C, condensing boilers expel hot vapour at only 60 °C or thereabouts. (Here we'll show you what this means for the modernisation of older systems.) Consequently, low temperature appliances are only viable in certain cases. For example, if you have several gas appliances connected to a single flue shaft in a multi-storey apartment building, if you only need to replace a single appliance or if it is not possible to renovate the entire system.

If homeowners purchase a condensing boiler and also insulate the heating system pipework, for example, they will benefit from heating cost savings as high as 30 %. Savings as high as approx. 50 % are possible in combination with solar thermal systems.


A solar thermal system can be an ideal addition to your gas heating system, because it combines the fossil fuel gas with free solar energy

Advanced condensing boilers are ideal in combination with solar thermal systems. A collector area of as little as four square metres is enough to meet more than half the annual demand for domestic hot water in a four-person household.

Solarkollektoren auf dem Dach eines Hauses
Environmentally responsible solar energy is free of charge and perfectly suited to supplementing a gas heating system.

If the solar thermal system is also intended to backup the heating system, the collector area must be at least twice as large, i.e. around eight square metres. This allows additional gas savings of between 10 % and 15 %. And if you complement your solar thermal system with an advanced condensing boiler, you'll qualify for state subsidies.


A gas heating system is more affordable than many other fossil-fuelled heat generators, both in terms of acquisition and operation.

The fact that gas is a clean energy source keeps the cost of servicing the heating equipment low. And you can also dispense with fuel storage equipment in your house.

Family at the table
Environmentally responsible solar energy is free of charge and perfectly suited to supplementing a gas heating system.

If you live in the countryside and don't have a natural gas supply, LPG is an efficient alternative to oil, coal, pellets or biomass. In combination with a solar thermal system or heat pump, there are also various subsidies available.


When using gas as a fuel, condensing technology naturally provides you with the highest efficiency. It is important here to consider the heating system (i.e. radiators, pipework and insulation) as a whole.

A new gas boiler with condensing technology may require all the radiators to be replaced, the pipework to be re-insulated or the flue system to be modernised. Although it is always possible to employ gas condensing technology in principle, the system efficiency can only be increased significantly in conjunction with these measures.

Condensing technology mostly requires the installation of a plastic flue system in existing chimney flues. This is because the low flue gas temperatures can otherwise lead to "fouling" of the chimney shaft with rot and mould.

Where you have several old, low temperature appliances connected to a single flue shaft, for example in a large apartment building, it is usually worthwhile updating all appliances to the latest condensing technology standard and modernising the flue shaft. Only where this is impossible, would it make sense – in exceptional cases – to select a low temperature appliance meeting the ErP standard, i.e. one which meets the European environmental standards. The best thing to do is contact a contractor who can check the system and the flue shaft for you.