Fire with system – authentic, simple & efficient
Building a good stove takes experience, precision, and technical expertise. BRUNNER’s system solutions combine the craftsmanship of traditional stove building with the advantages of modern prefabrication. Whether it’s a fireplace, tiled stove, or masonry heater – the foundation is always a high-quality BRUNNER wood-burning insert. Encased in heat-storing concrete elements or a raw steel shell, it becomes a user-friendly complete system that impresses both technically and aesthetically.
Installation is carried out by the stove builder – but much faster, easier, and more cost-effective than with a fully handcrafted stove. For those who appreciate real wood fire but want to avoid a long installation process, this is the perfect solution. And for anyone who prefers something more compact or minimalist, our IRON DOG® cast-iron stoves offer robust performance and distinctive character – ready to use right away.
The different System units & IRON DOGs®
System fireplaces BSK
System fireplaces are considered quick-response stoves because they provide immediately noticeable heat during the burn phase. The heating effect is generated through radiant heat from the large viewing window as well as warm air produced by metallic surfaces and an integrated heat exchanger.
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Room air enters through lower openings, is heated by the hot surfaces, and is then released back into the room as warm air. At the same time, the fireplace casing also heats up. In certain models, a small additional storage module extends the heat output even after the fire has gone out. The combustion air can be supplied from outside, and a special air guide keeps the viewing window clean and free from soot and dust.
System stoves BSO
System stoves are chosen when long-lasting heat is desired — warmth that remains noticeable even hours after the fire has burned down. Due to their operating principle, they belong to the category of slow-response stoves.
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Similar to a traditional storage stove, the heat energy from the flue gases is absorbed by the storage mass as it flows through and then gradually released through the stove’s surface over time. During the burn phase, the large viewing window of the firebox also provides direct and immediate radiant heat into the room. This characteristic heating principle is especially well known from traditional tiled stoves.
Compact storage stoves KSO
Compact storage stoves are pure storage heaters and true space-savers, featuring a slim column design with either a round or square footprint. The energy from the flue gases is absorbed in the fully ceramic firebox and as it passes through the storage mass, then released gradually through the surface over time.
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In terms of heating characteristics, they are true slow-response stoves. They take longer to heat up but retain warmth for many hours. Ideally, they are fired daily throughout the entire heating season. Compact storage stoves are an excellent choice when primarily radiant heat (as with a masonry heater) is desired, but space is limited.
System masonry heaters BSG
System masonry heaters, like traditional masonry heaters, are true heat storage wonders and are made entirely of high-quality chamotte material. Thanks to the properties of this material, the system masonry heater releases heat very slowly and evenly as radiant warmth, creating a comfortable indoor climate that lasts for many hours.
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Regular heating is essential for a masonry heater, as it should not be allowed to cool down completely in order to deliver its full performance. The storage material also needs some time to heat up. The system masonry heater is perfectly suited for passive houses and sustainable living concepts. Thanks to its ability to provide warmth for many hours with just a single load of wood, it proves to be particularly efficient for self-sufficient heating.
IRON DOGs®
Iron Dogs are a special kind of Swedish stove, crafted entirely in Germany from a single source. Made of durable cast iron, they are long-lasting companions with a timeless design. They not only create cozy warmth but also serve as inviting eye-catchers in any living space.
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The IRON DOG® models differ in many ways, such as size and function. However, every Iron Dog can be used for cooking, as each one is equipped with a hotplate. Above all, the IRON DOGs® are a true passion project for BRUNNER – a combination of our craftsmanship, experience, and enthusiasm for the extraordinary.
Which appliance is right for me?
| Property | System fireplace | System stove | System masonry heater | Compact storage stove | IRON DOG® |
|---|---|---|---|---|---|
| Type of heat | Radiant & convection heat | Radiant heat & heat storage | Slow, even radiant heat | Even radiant & convection heat | Radiant & convection heat |
| Firebox material | Steel | Cast iron | Chamotte | Chamotte | Cast iron |
| Outer cladding | Heat-storing concrete | Heat-storing concrete | Heat-storing concrete | Heat-storing concrete | Cast iron |
| Storage mass | Medium | High | Very high | High | Medium |
| Heat-up time | Fast | Medium | Slow | Medium to slow | Fast |
| Heat duration | Medium | Long | Very long | Long | Medium |
| Efficiency | High | Very high | Highest efficiency | Very high | High |
| Ambience & fire view | Very high (large glass panels) | High to medium (depending on model) | High to medium (depending on design) | High to medium (depending on design) | High |
| Special feature | Quick heat & fire enjoyment | Efficient heat for hours | Should be heated regularly due to long heat-up time | Efficient heat for hours | Quick heat & unique design |
| Ideal for | Transitional heating, atmospheric fire | Regular heating, pleasant radiant warmth | Continuous, self-sufficient wood heating | Regular heating, pleasant radiant warmth | Quick heat-up, atmospheric fire |
The system structure
The system casing is made of precisely fitting, structurally stable heat-storing concrete with internal reinforcement. The installation floor must be suitable for both static and thermal loads. The exact alignment of the base plate defines the vertical position or the angle to the installation wall. The heating insert is placed on this base plate, and the remaining elements are then assembled.
A minimal distance to adjoining walls can be achieved using heat protection panels. Openings for the flue pipe and combustion air duct are cut out with a jigsaw. If a ventilation system or kitchen exhaust (extraction mode) is installed in the building, it is advisable to include an external combustion air connection. This helps minimize the activation of the required safety monitoring system.
Boiler technology in system units
BSK & BSO
BRUNNER system fireplaces (BSK) and system stoves (BSO) are also available as water-bearing versions with different glass formats. In addition to their well-known features, these models offer the added benefit of domestic hot water production, supporting your existing heating system with warm water.
Whether you choose a water-bearing system stove or fireplace depends entirely on your personal preference and heating requirements:
- Do you want a large glass panel that provides plenty of fire atmosphere? Then a water-bearing fireplace is the ideal choice.
- Do you prefer a heating appliance that warms the room with comfortable radiant heat? Then the water-bearing stove is the better option.
How much heat is directed into the room or into the hot water system depends on your specific needs and heating setup. Moreover, the water-bearing models can be perfectly integrated into comprehensive heating concepts – transforming your heating system into an intelligent, energy-efficient solution.
The materials
Heat-storing concrete
Pure, authentic, and elegant – the fireplace body in its simplest form and expression. Precisely cast heat-storing concrete elements, assembled with shadow joints. The perfection here lies in imperfection. The concrete surface features edges and slight irregularities, which give it a refined and unobtrusive appearance.
It is highly recommended to seal the heat-storing concrete elements with carnauba wax after installation. This is strongly advised to permanently prevent unwanted stains. Once a hand or shoulder with natural skin oils touches the cool concrete surface, the resulting dark mark is nearly impossible to remove. Other liquids can also be absorbed by the concrete and permanently alter its appearance.
The BRUNNER system fireplace BSK can be assembled relatively quickly thanks to its precisely fitting heat-storing concrete components. It’s hard to imagine an easier or more affordable installation without sacrificing individual design options. Even a system fireplace can be customized – the casing can be extended, or the heat-storing concrete can simply be plastered or painted.
Raw steel
Raw steel is steel in its most original form, with its unique surface created through a special rolling process at high temperatures. During this process, a hard layer of iron oxide—known as scale—forms, giving the material its characteristic black-blue coloration.
Combined with its irregular, organic structure, where subtle color variations and individual patterns emerge, each BKO becomes a visual one-of-a-kind piece.
Cast iron
Cast iron has long been considered a high-quality material. It is the stove-building material with the highest thermal conductivity and contains a high proportion of carbon. For this reason, it cannot be shaped or forged but only cast. It is dimensionally stable, durable, and resilient — with no warping, no stress, and no scaling, even at high temperatures.
For example, our tiled stove inserts and IRON DOGs® are made from solid, premium cast iron. Why? Because these appliances are designed for high temperatures, long-lasting heat retention, and decades of reliable operation. Cast iron is simply unrivaled here — ensuring safety, durability, and heating comfort.
Our cast iron is 100% Made in Germany. Every BRUNNER cast component undergoes rigorous quality checks throughout the entire production process. This results in cast elements that meet the highest standards every single day. Each cast body is a piece of genuine German craftsmanship.
Surface design for heat-storing concrete
The surfaces of the fireplace casings are finished in raw concrete to allow for later individual design. Due to the manufacturing process, untreated surfaces may show variations in color tone, texture, or occasional marks. These differences can be balanced with a glaze-like color application. Any desired surface treatment is carried out after installation.
For a uniform and opaque color finish, temperature-resistant and water-vapor-permeable paints without solvent or plastic content are suitable.
Color variations, for example on extension rings, can be adjusted using a glaze-like color application. We recommend DecoLasur Matt, tinted in the color Slate 16, from Caparol’s product range. Each additional layer of glaze enhances the color intensity and increases the coverage of the raw concrete appearance.
To protect the untreated concrete look, we recommend treating the surface with carnauba wax. This surface seal preserves the natural character of the heat-storing concrete and highlights its existing texture. The silky gloss finish makes cleaning easy in case of dirt or stains. A later paint or plaster application is no longer possible after sealing.
Thermally resilient plaster coatings and surfaces with ceramic elements are individually designed and applied by skilled craftsmen.
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