FAQs

Kermi sells its products exclusively via a three-tier distribution system. This means that

• Kermi supplies specialist wholesalers.
• The wholesaler supplies the specialist partner.
• The specialist partner plans, sells and installs the products for the end customer.

This ensures that you as a customer receive professional advice, planning and installation - directly from trained and qualified specialist companies. We do not sell directly to end customers.

Specialist partners can use special online forms on the website to report a service case, request an initial operation or ask technical questions (e.g. about the heat pump or residental ventilation). Alternatively, a service number is available.

With the Kermi specialist partner search , you can quickly and easily find qualified installers in your area.

Our authorised specialist partners are on hand to provide you with professional advice, careful planning and expert installation.

Yes, as a private customer you can order spare parts directly from the Kermi spare parts shop. There you will find a large selection of original parts for radiators, shower enclosures, heating systems and ventilation technology. You also have the option of ordering spare parts from your specialist partner or installer if you need support with selection or installation.

The download centre is available to all users without registration. You can freely access installation instructions, brochures, technical data sheets and other documents at any time.

Kermi offers a comprehensive download centre where you can find all important documents at a glance.

Whether installation and operating instructions, brochures and technical data sheets - the right documents are conveniently available in PDF format for all product areas.

Yes, it often makes sense to replace old radiators. Outdated models often work inefficiently. They consume more energy and no longer provide the desired level of heating comfort. By replacing your radiators, you can significantly increase the efficiency of your heating system, save costs and improve your quality of living.

In principle, replacement is possible without any problems. However, classic (flat) radiators usually have a side connection, which is why some towel radiators are more practical for this than others. Special renovation solutions such as the KERMI Basic-D, Casteo-D and Duett-D models are the most suitable for replacement.

First of all, the required heat output must be right. This depends on the size of the radiator. The connections must also be taken into account. The least effort is required here if existing connections can be used again. Purely electric radiators, which only require a socket for the connection, have also proven to be a good alternative, especially for localised heating requirements.

It is important that the heating surface is large enough to achieve the required heating capacity. If space is limited, it may be worth reducing the installation distance of the pipes or installing panel heating in the wall. It is also important to bear in mind when switching from radiators to underfloor heating: Radiators are usually operated with higher flow temperatures than underfloor heating systems. An adjustment should therefore be made here if necessary, as temperatures that are too high with underfloor heating are perceived as uncomfortable.

Yes, this is possible without any problems! Modern heat pump radiators such as our X-Flair are specially designed to work efficiently with the low flow temperatures of a heat pump. Thanks to integrated fan technology, the heat is optimally manifolded in the room, resulting in fast and even heating. This allows you to enjoy a pleasant indoor climate and benefit from an energy-efficient heating system at the same time.

Choosing the right radiator depends on various factors, such as the size of the room, the desired heating capacity and the heating system. Our guide will help you find the ideal radiator for your needs - whether for a new build or modernisation.

Yes, with our upgrade sets you can give your old steel panel radiators a modern and stylish look in no time at all. The covers are manufactured to fit perfectly, can be fitted without drilling or screws and provide a quick and easy upgrade to your interior design. Thanks to the robust metal, they are durable and offer excellent thermal conductivity - a clear advantage over wooden or plastic panelling.

Hydraulic balancing ensures that each radiator in a building receives exactly the quantity of heating water it needs to heat the respective room efficiently and evenly. The first step is to calculate the heating load for each room, i.e. the amount of heat required to reach the desired temperature. Factors such as room size, insulation, number of windows and outside temperature are included in this calculation. Based on the heating load, the optimum water volume required by each radiator is then determined in order to avoid over- or undersupply. The pre-settable thermostatic valves are then adjusted so that they let through exactly this calculated water volume. If necessary, the heating pump is adjusted or replaced with an energy-efficient high-efficiency pump to optimise the water pressure in the system and reduce energy consumption. In addition, hydraulic balancing can often lower the flow temperature of the heating system, which enables further energy savings. Without hydraulic balancing, the heating water usually flows along the path of least resistance, which means that radiators close to the pump are oversupplied and radiators further away are insufficiently heated. This leads to uneven heat distribution, unpleasant flow noise, overheated or cold rooms and increased energy consumption. Hydraulic balancing distributes the water flow according to demand, resulting in even heat distribution, improved living comfort, reduced noise and lower heating costs. In addition, it is often possible to receive subsidies for this measure. Overall, hydraulic balancing ensures efficient, comfortable and environmentally friendly heating.

A floor stand bracket for radiators is a specially developed bracket that allows the radiator to be fixed directly to the floor rather than to the wall and positioned free-standing. This is particularly practical in situations where wall mounting is not possible or not desired, for example in listed buildings, floor-to-ceiling windows or special room design requirements. The floor bracket provides a stable base and secure footing for the radiator, while at the same time offering more flexibility when positioning it in the room. Floor brackets specially developed for KERMI convectors consist of a base plate and a matching cover, which are designed like half-panels. This creates a hollow space in the centre in which connection pipes can be routed inconspicuously from the floor to the radiator. In addition, an opening in the base plate allows the installation of a thermostatic sensor head without the pipes being visible. Floor brackets thus combine functionality, stability and an attractive design that blends harmoniously into the room.

The requirement class for radiators describes the loads that a radiator must be able to withstand at its place of use. It primarily refers to the fixing, stability and safety & security of the radiator and takes into account the various physical effects that can occur in everyday use – from harmless support, sitting or climbing to high loads caused by crowds of people in special situations. Originally, there were four requirement classes, of which requirement class one was deleted in the latest directive as it was rarely used in practice. It covered typical residential and office areas where no special loads are to be expected. Today, there are therefore three requirement classes, ranging from normal to very high requirements. The first class currently in force (requirement class two) applies to publicly accessible areas such as sales rooms or stairwells, where the radiator may occasionally be used carelessly. The third requirement class is intended for locations with high requirements, such as classrooms or escape routes, where radiators also serve as seating or must remain stable in panic situations. The fourth class stands for very high requirements and special loads, such as those found in prisons or psychiatric institutions, and requires particularly robust fixing. The division into requirement classes ensures that radiators are installed safely and stably in accordance with their environment in order to avoid damage and hazards due to loads.

As a rule, modern radiators already provide pleasant warmth in your own four walls at low flow temperatures, which are typical for heat pumps. Modern radiators have a larger surface area, which enables more even and better heat distribution. However, so-called heat pump radiators are particularly efficient when operated at low flow temperatures. These are specially designed to ensure optimum heat dissipation even at lower temperatures. Heat pump radiators have integrated fans (blowers) that distribute the warm air more quickly throughout the room. These fans significantly increase convection, more than doubling the air circulation and transferring heat much more quickly and efficiently throughout the room. This efficient heat transfer results in high energy efficiency, a pleasant indoor climate and lower operating costs. An example of such a radiator is the x-flair heat pump steel panel radiator from KERMI. It combines proven x2 technology with an integrated, fully automatic axial fan system that ensures rapid heating and effective heat distribution. The fans switch on and off as required and are particularly quiet. The x-flair is ready to plug in and is suitable for both new buildings and refurbishments. It also offers flexible connection possibilities and matches the look of other KERMI radiator versions. This makes it ideally suited to the requirements of low flow temperatures.

The KERMI therm-x2 Vplus steel panel radiators will be discontinued at the end of 2025. They will be replaced by the new KERMI therm-x2 Vmulti steel panel radiators. The Vmulti combines all connection versions of the previous Vplus versions in one model and also offers the option of swapping the valve from right to left. With six different connection possibilities, the Vmulti offers a high degree of flexibility, even in the event of short-term changes to the type of connection on the construction site, and complete design freedom with maximum availability. The range of sizes and colours remains identical to the previous Vplus product range. This change also applies to the respective x-flair versions, meaning that the x-flair Vplus will be replaced by the x-flair Vmulti at the end of 2025, thus also offering the extended connection possibilities and increased flexibility of the new model.

A heat pump absorbs free environmental energy from the surroundings. In a refrigerant circuit, the temperature is increased by compression and then transferred to the heating system.

The heat pump principle consisting of heat absorption, heat compression, heat transfer and expansion also works in cold winters and provides sufficient heat in the rooms. However, the more the absorbed environmental energy has to be increased, the more the refrigerant in the heat pump has to be compressed. This increases electricity consumption somewhat. However, this is usually only the case on a few days a year when temperatures fall well below 0 degrees.

A heat pump is first and foremost an environmentally friendly heating solution. But it can also be used to cool the building comfortably in summer. It extracts heat from the rooms and dissipates it to the outside. This effectively lowers the temperature inside the house. Compared to an air conditioning system, there is no draught.

Air source heat pumps generally work at all temperatures, but their efficiency decreases as the outside air temperature falls. The outdoor temperatures at which a heat pump works efficiently can be recognised by the addition of the COP value: COP 4.96 (A2/W35) means, for example, that at an outside temperature of 2 degrees and a flow temperature of 35 degrees, a very high coefficient of performance of 4.96 is achieved. This means that one kW of electricity generates 4.96 kW of heating energy.

Choosing the right heat pump depends on several factors, including

• Building type & insulation: new buildings often require less heating capacity than unrenovated old buildings.
• Heat source: Air, ground or groundwater - there are different options depending on the location and space available.
• Heating system: Underfloor heating or radiators? Heat pumps work particularly efficiently with panel heating.
• Hot water requirement: Households with higher hot water consumption require a more powerful solution.
• Funding opportunities: In many cases, there are government subsidies for installing a heat pump.

Whether air-to-water, brine / water heat pumps or water-to-water heat pumps - our guide will help you find the optimum solution for your home.

To maximise the self-consumption of your self-generated energy, e.g. from a photovoltaic system, the heat pump can be specifically integrated into the energy management system. An electricity storage unit helps to store surplus solar power and use it to operate the heat pump. In this way, you reduce the amount of electricity drawn from the grid, lower your energy costs and increase the efficiency of your heating system.

Yes, a heat pump can not only heat, but also cool. In the warm months, it extracts heat from the room and releases it into the environment. This works either via panel heating systems such as underfloor or wall heating or via special heat pump radiators. This allows you to enjoy a pleasant indoor climate all year round - efficiently and in an environmentally friendly way.

Yes, the installation of oil heating systems is still possible after 2025 under certain conditions, but different deadlines apply depending on the size of the city: In cities with more than 100,000 inhabitants, installation is permitted until 30 June 2026 at the latest, in smaller cities until 30 June 2028. A consultation regarding the economic efficiency must take place before installation in the existing building.

After 2026, oil heating systems may only be installed if they utilise a certain proportion of renewable energies, according to the provisions of the Building Energy Act (GEG).

From 2029, there will also be a gradual switch to so-called "green heating oil" - heating oil that contains a proportion of biogenic raw materials such as vegetable oils or used fats. Oil heating systems installed after mid-2026 (or 2028) must be operated with at least 65 per cent green heating oil from the outset.

In view of these requirements and, above all, for ecological reasons, it makes sense to (fully) switch to renewable energies now.

The Building Energy Act (GEG) of 2024 does not prescribe the general replacement of oil heating systems. However, replacement is mandatory for oil heating systems with an output of between 4 and 400 kW that are more than 30 years old and use constant temperature technology. The chimney sweep determines this obligation and informs the owner. There are exceptions for owners of detached and semi-detached houses who lived in the house before 1 February 2002 - the replacement obligation does not apply here. In the event of a change of ownership after this date, the new owner has two years to replace the old oil heating system. Oil heating systems that were installed before 1 January 2024 and do not fall under the replacement obligation are protected until the end of 2044 and may continue to be operated and repaired. Oil boilers with modern condensing or low-temperature technology are exempt from the replacement obligation. However, switching to renewable energies not only makes sense from an ecological point of view, but is also financially supported by various subsidy programmes.

A new oil heating system with modern condensing technology may be more efficient than older models, but it is not very sustainable in the long term. The Building Energy Act (GEG) increasingly restricts the use of fossil fuelled heating systems: Oil-only heating systems are already no longer being installed in new builds, while minimum proportions of bio heating oil will apply to existing buildings from 2029, rising to 60% by 2040. Oil heating systems will be completely banned from 2045. There are also many other reasons not to install them: oil heating systems cause higher CO₂ emissions and particulate matter, are dependent on fluctuating oil prices and rising CO₂ taxes, require space for the oil tank and are no longer subsidised. In the long term, this can have a negative impact on property value. This is why switching to renewable heating systems is usually the more sensible and sustainable choice.

The coefficient of performance of a heat pump is also called COP (coefficient of performance) and is an important indicator of efficiency. The COP value always refers to a defined operating point and describes the ratio of electrical power consumed to heat output delivered. A COP value of 4.96 (A2/W35) for an air/water heat pump means, for example, that at an air temperature of 2°C (=A2) and a flow temperature of 35°C (=W35), 1 kW of electrical energy produces 4.96 kW of heating capacity. In principle, therefore, the higher the COP value, the more efficiently the heat pump works and the less electricity it requires to operate.

Yes, heat pumps are also a sensible and environmentally friendly heating solution for old buildings. They utilise free energy from the air, water or earth, making you independent of rising oil and gas prices. However, in order for the heat pump to work efficiently in an old building, a few requirements must be met: Good insulation of the roof, façade and windows is important to minimise heat loss. It should also be checked whether the existing radiators can provide the desired level of heating comfort even with the lower temperatures of the heat pump. Replacing the old radiators with special, particularly efficient heat pump radiators may make sense here.

Heat pumps can also be operated with modern (flat) radiators without any problems. The flow temperature - i.e. the temperature to which the water is heated before it enters the heating circuit - is crucial for efficient operation. Heat pumps work particularly efficiently at low flow temperatures. For this reason, radiators should be used that bring the desired thermal comfort into the rooms at such low temperatures. Older radiators often do not achieve this and should be replaced with modern radiators. Special heat pump radiators, which are optimised to the requirements of the heat pump and thus enable maximum efficiency, are particularly effective.

The structural requirements for the installation site differ depending on the type of heat pump. Air-to-water heat pumps are the easiest to install. A stable substrate should be available for outdoor installation. Devices for indoor installation require a room, e.g. in the basement, that has load-bearing capacity and is well ventilated.

Brine / water heat pumps, on the other hand, require geothermal collectors to be laid over a large area or geothermal probes to be installed at depth. This requires either a large, unsealed area (collectors) or a soil expertise (probes). For water-to-water heat pumps, two wells must be drilled to transport the groundwater to the heat pump. As a rule, this access must be authorised.

Due to these structural preparations, brine / water heat pumps are usually more suitable for new buildings or major refurbishments, while air / water heat pumps are also suitable for retrofitting existing buildings.

Whether a permit is required depends on the type of heat pump. Air-to-water heat pumps and brine / water heat pumps with geothermal collectors generally do not require a permit, as no deep drilling into the groundwater is necessary. With air-to-water heat pumps, however, attention should be paid to the distance to the neighbouring property, as the devices can cause noise during operation.

For water-to-water heat pumps, on the other hand, a permit is required as deep drilling is required and groundwater is used. The regulations vary depending on the federal state. It is therefore important to obtain information in advance from the relevant water authority and the geological service.

A combination of heat pumps and photovoltaic systems is not only easily possible, but also makes sense. Heat pumps require electricity to operate. By combining them with photovoltaic systems, they can be operated with self-generated, green electricity in a way that conserves resources and saves costs. The x-change dynamic heat pumps from KERMI enable the intelligent use of PV electricity to generate heat on demand thanks to the built-in power-to-heat function. The heat generated is stored in a heat storage unit and is then available when needed.

Choosing the right residental ventilation system depends on various factors such as the size of the house, the number of people in the household and the desired energy efficiency. Our various ventilation models offer solutions for every need - from simple decentralised ventilation to more complex systems with heat recovery. Use our guide to find the system that best suits your home and your requirements.

You can conveniently purchase new filters for your residental ventilation system from our KERMI spare parts shop or from your specialist partner. This way, you can ensure that your ventilation system is always equipped with suitable, high-quality filters.