Last updated: August 10, 2021

Welcome to our big gas heater test 2021. Here we present all the gas heaters we have tested in detail. We have compiled detailed background information and added a summary of customer reviews on the internet. We would like to make your purchase decision easier and help you find the best gas heater for you.

You will also find answers to frequently asked questions in our guide. If available, we also offer interesting test videos. Furthermore, you will also find some important information on this page that you should definitely pay attention to if you want to buy a gas heating system.


  • A gas heating system is usually operated with natural gas. Both the rooms and the water can be heated.
  • There are also several options with which the gas heating can be used. In addition to various heating gases, some models have an external water storage tank, which pays off if the water requirement is particularly high.
  • It is also possible to supplement the gas heating with, for example, solar thermal energy, in order to reduce electricity costs on the one hand and to make a positive contribution to the environment on the other.

The Best Gas Heating: Our Choices

Guide: Questions you should ask yourself before buying a gas heating system

What is a gas heater?

A gas heating system is nothing more than a heating system that uses a certain gas to heat the room(s). Depending on the installation, either radiators are supplied with heat, which is then distributed via the air, or the gas is distributed via pipes in walls and/or under the floor, so that these are responsible for heating the rooms/space.


Gas heating is powered by gas and therefore has several advantages. (Image source: / ri)

There is also the option of using natural gas or liquid gas as the heating fuel. Both options can be used for effective heating. However, liquid gas is more expensive and an additional liquid gas tank is required, which requires more space and is more expensive. Natural gas, on the other hand, requires a gas connection and an installed pipe system, which is not the case with LPG.

Alternatively, biogas can also be used. To be precise, this is natural gas that is produced by fermenting biomass in biogas plants. It is therefore considered climate-neutral, even though a high demand at the same time promotes monocultures, which in turn have a negative impact on the agricultural landscape.

What are the advantages and disadvantages of gas heating?

Probably the biggest advantage of gas heating is its low cost. The initial costs are limited and the heating gas can usually be purchased very cheaply. In addition, gas heating systems require less space than other heating systems. Modern boilers can also reduce fuel consumption. Gas heating systems can also be combined with renewable energies.

Thus, it is possible to run a solar system at the same time, which is applied exactly when the sun provides enough energy. However, the purchase is also associated with some hurdles. For example, the installation of the pipe system is often extremely complex. In addition, either a gas connection or a liquid tank is required. If natural gas is used, it should be borne in mind that the source is a fossil fuel. In other words, the emission of CO2 damages the environment.

In addition, the purchase costs can be reduced even further through subsidies. The subsidy programme of the Kreditanstalt für Wiederaufbau (KfW), for example, offers the programme KfW 430 - "Energy-efficient renovation", with which one can get back up to 15 % of the costs of the gas heating. These costs include not only the gas heating itself, but also the costs of installation, modifications to the chimney and removal of the old system.

If the system is combined with solar thermal energy to heat water, a grant from the Federal Office of Economics and Export Control (BAFA) is also possible, with savings of up to 1,000 euros. If the solar thermal system has a heating-support function, up to 3,600 euros are possible.

However, in this case the KfW 430 programme - "Energy-efficient renovation" only offers up to 10 % inclusive instead of 15 %.

For whom is a gas heating system suitable?

Depending on the model, a gas heating system can be used for a specific floor or flat, as well as for single-family homes or even apartment buildings. If it is a central heating system, for example, many rooms in combination with several floors can be supplied at the same time.

Wall-mounted units, on the other hand, are characterised by quick installation and small space requirements. However, they also have a lower maximum output. As a rule, such units are offered with a maximum output of up to 35 kW.

Due to its relatively low initial costs and the low gas costs, a gas heating system is particularly suitable for people who want to heat effectively as well as save money. It is not uncommon for such costs to be offset by the savings after just a few years

Decision: What types of heaters are there and which is the right one for you

Basically, you can distinguish between eight different types of heaters:

  • Electric heating
  • Gas heating
  • Pellet heating
  • Oil heating
  • Heat pump#
  • Wood heating
  • CHP
  • Solar heating

In the following, we explain the different types and their respective advantages and disadvantages. In this way, we want to help you find the most suitable heating system for you.

What is an electric heater and what are its advantages and disadvantages?

Electric heaters, as the name suggests, work with electricity. This means that heat can be generated without the need for specific piping systems or the like.

  • Quick installation
  • Low purchase costs
  • Enormous variety of products
  • Can be used easily
  • Extremely high electricity costs may be incurred

The prerequisite is simply a power connection. In addition, the purchase costs are low. Nevertheless, relatively high electricity costs are usually incurred.

What is gas heating and what are its advantages and disadvantages?

Gas heaters usually work with natural gas. Alternatively, liquid gas or biogas can be used. Gas heating systems are characterised by extremely low purchase and operating costs.

  • Extremely low operating costs
  • Low purchase costs
  • Subsidies are possible
  • Installation is complex
  • Not environmentally friendly due to the production of CO2

However, depending on their nature, they require an external LPG tank or a piping system. Therefore, installation can be costly.

What is pellet heating and what are its advantages and disadvantages?

Pellet heaters use wood combustion to heat the rooms. They also work automatically and can use wood residues as heating material. The fuel itself is stored in a kind of tank. It is often sufficient to fill it up once a year.

  • Use of renewable and recycled wood
  • Operation is automatic and efficient
  • High efficiency is guaranteed thanks to the use of calorific value
  • High space requirement
  • High initial costs
  • The ash should be removed at regular intervals

What is oil heating and what are its advantages and disadvantages?

Oil heating systems use oil as a heating medium. This is burnt in the boiler and then fed to the respective components. In this way, both rooms and water can be heated. After gas heating, oil heating is the most widespread type of heating in Germany, with almost six million households.

  • Tried-and-tested and reliable technology
  • heating oil can also be purchased in stock
  • low emissions
  • no need to connect to district heating or gas networks, for example
  • Heating oil prices are variable and unpredictable
  • space required by the boiler

What is a heat pump and what are its advantages and disadvantages?

Heat pumps draw heat primarily from the air, groundwater and the earth. The extracted heat is then stored and can be used to heat rooms and water.

  • Low electricity costs
  • Saves resources
  • Requires almost no maintenance
  • No chimney necessary
  • Installation depends on local conditions
  • More inefficient than gas or oil heating systems, for example

This makes it an extremely resource-saving technology. In addition, only small amounts of electricity are required for operation.

What is wood heating and what are its advantages and disadvantages?

Wood heating, as the name suggests, uses wood as fuel. This type of heating works in three phases; first, the material is heated to extract the moisture it contains, then it is heated to a certain temperature. Finally, the appropriate gases, such as oxygen, are added to the heated material.

  • Wood prices are not rising as rapidly as gas and oil prices
  • Only the amount of CO2 is emitted that the wood has absorbed
  • Acquisition costs are high
  • High space requirement
  • Maintenance costs are above average

What is a CHP unit and what are its advantages and disadvantages?

A combined heat and power unit (CHP) combines the generation of electrical energy and heat. While electricity is produced, the heat generated in the process is stored and can then be used.

  • Produces both heat and electricity
  • Ecologically sustainable
  • Acquisition costs are high
  • Installation requires a lot of space

There are several types of engines, from diesel and steam to gas turbines and fuel cells. The fuels used can be just as diverse. Biogas or vegetable oils, as well as wood, are considered particularly sustainable.

What is solar thermal energy and what are its advantages and disadvantages?

Solar thermal energy is a collective term for devices that are able to use the energy of sunlight. Whether solar thermal energy can completely replace conventional types of heating depends, among other things, on the location and the structural substance.

  • Energy source is free of charge and environmentally friendly
  • maintenance costs are low
  • Acquisition costs are high
  • previous knowledge is necessary for optimal location
  • permits may be required

It is assumed that in the case of hot water, about 50 to 65 % of the annual demand can be covered.

Buying criteria: These are the factors you can use to compare and evaluate gas heaters

In the following, we will show you which criteria you can use to compare and evaluate gas heaters. This will make it easier for you to get an overview and decide on a suitable and effective model. In summary, these are the following criteria:

  • Power
  • Size
  • Installation

In the following, you can read about the respective criteria and find out why it makes sense for you to purchase a model based on the criteria or not.


The output is given in kW and refers to the boiler. The required output depends largely on the area to be heated, as well as the material and condition of the building. Older buildings, for example, require significantly more heating power on average than newer ones.

For private customers, a heating capacity of eight to 15 kW is usually required. If the water is also to be heated, an additional output of 0.25 kW per person should be calculated. This refers to a water volume of 50 litres per person at a temperature of 45 degrees Celsius. The following table is also a guideline for orientation:

Type of building kWh per square metre
New building (according to Wärmeschutz - EnEV 2002) 0.045 to 0.060 KW per m²
New building (according to Wärmeschutzverordnung 1995) 0.050 to 0.060 kW per m²
Buildings constructed before 1995 (normal thermal insulation) 0.070 to 0.090 KW per m²
Old buildings (without special thermal insulation) about 0.120 kW per m²


Depending on the living situation, not every boiler is an option because of its size. Gas heaters with a liquid tank in particular take up a lot of space and are therefore unsuitable for flats, for example. Floor-standing heaters generally take up a lot of space, which is why wall-mounted heaters are the better choice for smaller living spaces.


A gas heater with a liquid gas tank takes up additional space. Nevertheless, installation is otherwise straightforward. With natural gas or biogas, for example, the situation is different; this is distributed via pipes in the walls and/or under the floor.

Thus, the installation of a pipe system in the house/flat is unavoidable. On the one hand, this involves additional acquisition costs, and on the other hand, this option is usually only available to property owners.

Facts worth knowing about gas heating

Gas heating in combination with solar thermal energy

In order to keep both CO2 emissions and operating costs as low as possible, a combination with solar thermal energy is a good idea. Solar systems can absorb and store energy from the sun when it shines.

This can then be used to provide hot water. How effective this combination is, or how much energy can be absorbed from the sun, depends on several factors. These include the following:

  • Solar area
  • Position of the solar surfaces
  • Weather conditions (→ frequency and intensity of solar radiation)
  • Technology and quality of the solar heating devices

If the efficiency is high, the solar thermal system may even be able to take over a large share of the heating of the living space. However, it should not be forgotten that the initial costs of solar thermal energy are often high and therefore only prove to be financially worthwhile after many years.

Image source: / ri

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