Frequently asked questions – BRUNNER FAQ
Here you’ll find a list of common customer questions where you might already discover the answers you’re looking for. And if there’s still something keeping you up at night, don’t hesitate to reach out to us.
You’ve got questions, we’ve got the answers
When planning a stove or heating system, certain questions are bound to come up—even if you’ve already decided on a BRUNNER appliance. That’s because a tiled stove or log wood boiler is no longer just a simple wood-burning unit, but a sophisticated, complex product designed to meet customer expectations, environmental standards, and visual aesthetics alike.
That’s why in the BRUNNER FAQ you’ll find detailed explanations on all the key topics related to stoves, fireplaces, and boilers.
General information about fireplaces, tiled stoves & more
- Why is it called tiled stove and not tile?
The term tiled stove is always used among experts when referring to stoves – especially tiled stoves. Ceramic components are produced in a special production process, and their special geometry makes that they are fixed in place with clamps during construction. Tiles, on the other hand, are flat slabs fired from white clay and painted or printed. They are mainly used as wall and floor coverings in kitchens or bathrooms.
- What is the difference between system fireplaces and heating inserts?
Heating inserts are the heart of a fireplace or tiled stove and are individually combined by stove builders with a cladding of their choice. They consist of the combustion chamber and the technology, but the exterior design is freely planned and built.
System fireplaces and system stoves are preconfigured complete solutions with modular cladding made of thermal concrete – for quick and easy installation. While heating inserts offer maximum design freedom, system solutions enable time-saving assembly with prefabricated components. - What is the difference between system stoves and system fireplaces?
Both are preconfigured complete solutions with modular cladding made of thermal concrete. The difference is the wood fire insert and the resulting thermal effect.
If atmosphere is the primary requirement, then a system fireplace is the right choice. With a steel wood fire insert inside and the option of large glass panes, the heat generated is quickly released into the room. The fireplace therefore warms up quickly, but also cools down again quickly.
In contrast, a system stove provides long-lasting heat thanks to its cast-iron insert and a downstream storage mass. It has a powerful heat output and continues to provide heat for some time even after it has burnt down. - Can I install a system device myself?
No, because a fireplace or stove is a thermo-physical, interior design element. This means that it must not only meet visual requirements, but also technical ones. Just like central heating, correct installation is important for flawless operation.
- What does “green” mean for system fireplaces?
Every Brunner system fireplace is equipped with a fireplace insert from the BKH green series. This new generation of fireplace inserts stands for optimized combustion technology with lower emissions and higher efficiency. As a result, Brunner system fireplaces are particularly efficient, environmentally friendly and future-proof – and have the “green” in their name.
In addition, every Brunner system fireplace can be upgraded to green+. A BRUNNER combustion control system and a catalytic converter are integrated. This gives BRUNNER customers the security they need to be able to react if limit values become even stricter.
- What is a storage heater/masonry heater?
A masonry or storage heater is a type of tiled stove construction-type in which the energy produced in the combustion chamber is released into the room with a delay of several hours. The combustion takes place in a masonry combustion chamber. The heating gases flow through the draught channel of the heat storage, which charges like a “heat accumulator”. This energy load is slowly released across the surface as gentle radiant heat. When planning, the furnace builder determines the heat output across the stove surface and the wall thickness temperature. The storage capacity is influenced by the weight.
- What is a hot air stove?
The hot-air stove is a type of tiled stove in which the energy released during the combustion phase is quickly converted into heat. A free-standing cast iron heating insert with lateral metal reheating surface is placed in the stove cladding. The room air flowing in through openings in the base area heats up on the hot surfaces and flows as convection air, usually through ventilation grilles, into the installation room.
- What is the difference between rated heat power and combustion heat power?
Rated heat power is the effective heat delivered to the living space. Combustion heat power is the heat released by the fuel in the firebox. Especially in the case of stove systems with large storage volumes, where the energy is released with a delay over a long period of time, the rated combustion power and the rated heat power can differ significantly.
- What material are sealing cords made of?
Sealing cords consist of E-glass or silicate fibres. They are heat-resistant and harmless to health.
- What are the properties of glass ceramics?
Ceramic glass does not expand when heated – therefore no stresses build up in this material. There is no danger of stress cracks or breakage even when it cools down quickly. Ceramic glass can be loaded up to 700 degrees Celsius. At higher temperatures, the glass becomes milky cloudy; however, the strength is not significantly changed by this.
Viewing glass faces are best cleaned with a damp (not wet!) paper towel. Stubborn dirt can also be removed with a damp paper towel dipped in a little wood ash. Avoid cleaning agents or special foam cleaners. Their ingredients attack the oven seals on contact and are damaging.
- Why a fireplace, tiled stove or boiler?
The unique atmosphere of a wood fire is still the cosiest and most pleasant heat source. It has accompanied people for thousands of years. At the same time, wood is a natural, renewable raw material whose combustion does not release any harmful flue gases or toxins. This is another reason why more and more people are heating their entire homes with wood. Regardless of the effects of global political crises, regional wood removal is strictly regulated and controlled. A home to feel good in, all with a clear conscience. This is exactly what fireplaces, tiled stoves and boilers by Brunner stands for.
- When do i need a negative pressure safety control?
The negative pressure safety control (USA) is required if the negative chimney pressure must be monitored. This is always the case if the pressure conditions in the installation room or in the combustion air system of the fireplace are influenced by ventilation systems such as extractor hood, living room ventilation, hoover system or clothes dryer. As soon as the negative pressure in the chimney falls below the minimum value, the ventilation system, extractor fan etc. are deactivated. With the USA, any number of ventilation units can be connected (maximum permissible switching capacity 2A). However, only one fireplace can be monitored.
Brunner Product range
- Why are BRUNNER’s EOS/EAS more expensive than competitors products?
BRUNNER combustion and stove controls not only ensure greater ease of use (place the wood on the stove, light it and you no longer need to worry about the rest of the combustion process), they also contribute to a special level of safety. To avoid any safety hazards, the stove must not be in any operating condition. EOS and EAS monitor all components. Safety-relevant components such as the door contact switch are duplicated or equipped with additional sensors. Only if both signals match, the component is working according to regulations. The safety concept always requires feedback. This is unique and only available at BRUNNER’s.
- What does “green” mean for system fireplaces?
Every Brunner system fireplace is equipped with a fireplace insert from the BKH green series. This new generation of fireplace inserts stands for optimized combustion technology with lower emissions and higher efficiency. As a result, Brunner system fireplaces are particularly efficient, environmentally friendly and future-proof – and have the “green” in their name.
In addition, every Brunner system fireplace can be upgraded to green+. A BRUNNER combustion control system and a catalytic converter are integrated. This gives BRUNNER customers the security they need to be able to react if limit values become even stricter.
- Can i buy BRUNNER online?
People’s buying behaviour is leading them further and further towards online retailing and consequently there are now also some retailers who sell BRUNNER products on their online shop. Legislation does not allow us to prevent this, but we do not support it. We are firmly convinced that only systems built by trained experts promise the quality that BRUNNER wants to offer, and we only provide a guarantee on products that have been installed by qualified tradesmen.
- Why does BRUNNER make wood heating systems an wood fires?
Because we simply love the raw material of wood and our nature. And that is why we are convinced that wood heaters and wood fires are the perfect contribution to a healthy and sustainable environment.
- Where are BRUNNER products manufactured?
Our cast-iron heating inserts for tiled stoves and our cast-iron stoves in the “IRON DOG” range, for example, are manufactured in our own ironworks in Ortrand, Saxony. Our fireplace inserts are developed and assembled in Eggenfelden, Bavaria. And our boilers come from the Bavarian Forest. Before all these products are delivered to the tradesman, they are also put to the test once again and checked by hand by our experienced technicians.
It is important to us that we can stand by the quality of our products. And only this complex but valuable production chain enables us to do just that.
- Why a fireplace, tiled stove or boiler?
The unique atmosphere of a wood fire is still the cosiest and most pleasant heat source. It has accompanied people for thousands of years. At the same time, wood is a natural, renewable raw material whose combustion does not release any harmful flue gases or toxins. This is another reason why more and more people are heating their entire homes with wood. Regardless of the effects of global political crises, regional wood removal is strictly regulated and controlled. A home to feel good in, all with a clear conscience. This is exactly what fireplaces, tiled stoves and boilers by Brunner stands for.
- Where can i get BRUNNER products?
Our products are only available from qualified specialist dealers. Experienced stove and heating installers guarantee that the installation of our high-quality products also runs smoothly. In this way, we can offer the best quality and excellent service for decades.
- When do i need a negative pressure safety control?
The negative pressure safety control (USA) is required if the negative chimney pressure must be monitored. This is always the case if the pressure conditions in the installation room or in the combustion air system of the fireplace are influenced by ventilation systems such as extractor hood, living room ventilation, hoover system or clothes dryer. As soon as the negative pressure in the chimney falls below the minimum value, the ventilation system, extractor fan etc. are deactivated. With the USA, any number of ventilation units can be connected (maximum permissible switching capacity 2A). However, only one fireplace can be monitored.
- Why is a BHZ useful?
The BRUNNER heating center (BHZ) offers an efficient and flexible solution for integrating various heat and power generators and consumers. It ensures demand-based energy storage and distribution, maximizes energy efficiency and enables simple adaptation to individual requirements. In combination with the BRUNNER energy manager, the BHZ optimizes the control of the entire heating system and ensures future-proof, sustainable use of heat and energy.
- Can I retrofit a BHZ?
Yes, the BRUNNER heating center can be easily retrofitted. It has a modular design and can be integrated into existing heating systems. The BHZ can also be combined with third-party products. The BHZ expands and optimizes your heating technology to increase efficiency and enable better use of renewable energies.
- Does a BHZ only work with BRUNNER products?
No, the BRUNNER central heating system is designed to be compatible with many common heating systems and heat generators, including those from other manufacturers. It can be flexibly combined with various fossil and regenerative heating sources such as log, pellet and wood chip boilers or oil and gas heating systems as well as heat pumps and solar systems. As a result, it offers a high degree of flexibility and adaptability for individual heating solutions.
Correct Heating
- Which wood can i burn?
Only untreated split logs including adhering bark are suitable and permitted for combustion in individual fireplaces. The logs must be stored until the moisture content has reached a maximum of 20 percent. Coated, varnished or treated wood must not be burnt.
- How do i store firewood correctly?
It is best to store firewood loosely stacked in piles, if possible in sunlight, well ventilated and protected against rain. Unsuitable is the storage of wood in damp, closed rooms without ventilation.
- Can coal und wood briquettes also be burnt?
The stainless furnace is ideal for wood fuel, but not for coal. Coal needs combustion air from below into the stack while being able to shake off the embers and remove ash. Therefore, coal cannot be burnt. In addition, the fireclay is specially designed for wood; if coal is burnt, the fireclay will be damaged in a short time. But wood briquettes according to DIN 51731, size class HP2,may be used at any time.
- What fuels are used in a tiled stove central heating system?
Logs and/or wood pellets are used as environment-friendly fuels for tiled stove central heating systems. With pellets, the tiled stove central heating system can be operated fully automatically. This guarantees the highest heating comfort and at the same time independence from fossil fuels.
In buildings with a low energy demand, the entire heat, heating and hot water demand can be generated by a tiled stove central heating system. This eliminates the costs for an additional heating device.
Replacing a tiled stove insert: what you need to know
- What is the right heating insert?
Replacing a heating insert sounds worse than it is. Ideally, only the insert itself is replaced, while the stove casing remains. The old heating insert is simply disconnected from the heat recovery surface of the tiled stove by detaching the flue pipe and pulled out like a drawer. The new insert is pushed onto the same support frame and the flue pipe reconnected.
For added convenience, an electronic combustion air control can also be installed. And for anyone switching from a grate firing system with coal to wood, a grate-free insert can be used without complication.
To determine in advance which heating inserts are suitable in terms of dimensions, a selection guide is available for installers. It lists all common inserts from the past decades for which the legislator has set a replacement deadline.
- Does the heat recovery box also have to be replaced?
In case of a tiled stove with a heat recovery box that needs to be replaced, we also recommend renewing the metal heat exchanger surface. It must be decided individually whether this can be done without dismantling the stove casing, depending on the installation situation and geometry – in other words, whether the effort is reasonable.
Strictly speaking, the tiled stove insert and the heat recovery box are type-tested together according to DIN EN 13229. When replacing, the metal heat recovery box must also be renewed. Replacement of the insert without the heat recovery box is only possible if the box is compatible with the new insert and the heat exchanger surfaces match closely. Suitable boxes are made of cast iron with a minimum wall thickness of 4 mm or of steel/stainless steel sheet with a minimum thickness of 2 mm.
In principle, the on-site situation and the technical condition of the heat recovery box must be considered. Depending on its condition, it may be better to replace the stove insert together with the heat recovery box.
- Are there retrofit kits?
Retrofitting an existing heating insert with so-called retrofit kits is listed in the 1st Federal Immission Control Ordinance (1. BImSchV) as a possible solution. A retrofit kit may consist of baffle plates, ceramic foam, or the replacement of functional parts. When offering such retrofits, the manufacturer must take responsibility for ensuring that the emission and efficiency values in the test report are met after retrofitting. The retrofitted appliance must be type-tested by the manufacturer and is entitled to carry the CE mark.
The authorized district chimney sweep should be involved before retrofitting. Responsibility lies with the manufacturer of the appliance. Installation of the retrofit kit may not be carried out by the manufacturer, but by a specialized company. Afterwards, the authorized district chimney sweep performs the official acceptance.
Note: Heating inserts were tested under national DIN standards (e.g. DIN 18892) before 2001. These old DIN test requirements included repeat testing every six years. In selected cases, the last tested condition, possibly exempt from replacement, can be restored by retrofitting combustion chamber components.
The installation of a retrofit kit should always be assessed in relation to the age of the appliance. It is a practical solution when fireplace inserts, tiled stove inserts, or similar units are permanently built in and replacement would be disproportionately complex.
- Is the year of manufacture always decisive?
Heating inserts were tested under national DIN standards before 2001. Testing had to be repeated every six years. The last test carried out for the insert is decisive, as long as no major design changes have been made.
This information is documented and stored in the HKI database, where the replacement date can be found.
- Are open fireplaces affected?
Open fireplaces or open wood-burning appliances are not classified as heating devices by German law. They are not subject to the replacement requirement and may continue to be used, but only occasionally.
There are various official guidelines and legal rulings on how to interpret the vague term “occasional use”:
- Berlin Court of Appeal: limited to one day per week for six hours (judgment of March 26, 2013, ref. 21 U 131/08)
- Higher Administrative Court of Rhineland-Palatinate in Koblenz (1991): limited to eight days per month for five hours (decision of April 12, 1991, ref. 7 B 10342/91)
However, these rulings cannot be considered a general nationwide standard. In principle, it is prohibited to use an open fireplace regularly or as a permanent form of home heating.
- Are there special regulations in the cities?
To ensure consistent enforcement of the 1st Federal Immission Control Ordinance (1. BImSchV), various questions have been addressed by the Federal/State Working Group on Immission Control (LAI). These answers, enforcement aids and guidelines have been coordinated within the state immission control authorities. They are recommendations, from which the federal states may deviate. Fuel ordinances in major cities or metropolitan areas sometimes tighten the requirements of the 1. BImSchV for operating wood-burning appliances.
- In Munich, only wood-burning appliances that meet Stage 2 of the 1. BImSchV may be operated.
- In Stuttgart, special regulations apply for the operation of wood-burning appliances during “fine dust alerts.”
- Can the chimney sweep require additional fire protection measures?
When a heating insert is replaced or retrofitted, it is considered a significant modification of the appliance under the 1st Federal Immission Control Ordinance (1. BImSchV). This means:
1. Under the 1. BImSchV:
a) the flue conditions (chimney) must be reassessed according to §19 of the 1. BImSchV, and
b) proof of compliance with the applicable requirements for this appliance according to Annex 4 of the 1. BImSchV must be provided.2. Under building law:
a) the above requirements must be proven through type testing by the manufacturer, and
b) any additional building code requirements (e.g. safety distances to combustible materials) must be observed,
c) the appliance may only be put into operation once the authorized chimney sweep has certified the suitability and safe usability of the heating appliance (according to MBO) and the flue system (according to LBO). - Who checks compliance with the requirements?
The authorized chimney sweep checks whether the existing appliance meets the new requirements or needs to be replaced. Proof can be provided by the entry in the HKI database or the manufacturer’s declaration.
A “traffic light system” is used to classify and mark the existing wood-burning appliance for the operator:
- Red means: “The insert is already over 40 years old and overdue.”
- Graduated orange tones indicate the deadlines 2017, 2020 and 2024, showing by when the appliance must be decommissioned, retrofitted or replaced.
- Green means the wood-burning stove may continue to be operated.
- Are there any exceptions?
The legislator has exempted the following types of fireplaces from replacement, retrofitting or decommissioning requirements:
- Non-commercial cookers and baking ovens with a rated heat output below 15 kW
- Open fireplaces
- Masonry heaters built by craftsmen
- Individual room heating appliances in residential units where these are the sole source of heat and no other heating system is available (e.g. radiators)
- Individual room heating appliances that can be proven to have been manufactured or installed before 1 January 1950
- No manufacturer’s declaration available – what are the alternatives?
If no manufacturer’s declaration or test certificate confirming compliance with the limit values is available, the legislator provides the following alternatives to replacing or decommissioning the appliance:
- Individual approval/measurement by the chimney sweep (dust: 0.15 g per cubic meter, carbon monoxide: 4 g per cubic meter)
- Built-in fireplace inserts, masonry heater inserts or comparable stove inserts can be retrofitted with an additional device for dust reduction in line with the current state of the art.
Important to note:
- Proof of compliance through a chimney sweep’s measurement is not always possible and may also result in a negative outcome.
- Installing a so-called “dust filter” is costly. Dust filters must also be serviced regularly in accordance with the manufacturer’s specifications.
These alternative measures should always be considered in relation to the age of the heating appliance. They offer a potential solution if fireplace inserts, masonry heater inserts or comparable stove inserts are permanently built in.
- When does the old stove insert need to be replaced?
The German legislator has set deadlines for the decommissioning or replacement of old appliances: if the transitional limits for CO emissions and fine dust cannot be proven to be met, the appliances must be retrofitted or taken out of service. The deadline depends on the date indicated on the appliance’s type plate.
Date on type plate Deadline for retrofitting or decommissioning
Up to and including 31.12.1974
(or if the date is no longer identifiable) 31.12.201401.01.1975 – 31.12.1984 31.12.2017
01.01.1985 – 31.12.1994 31.12.2020
01.01.1995 – 21.03.2010 31.12.2024
- How can I see if my stove insert needs to be replaced?
The type plate on your stove, fireplace or wood-burning insert shows the make and model. With this information, you can check on the HKI website (Industrieverband Haus-, Heiz- und Küchentechnik e.V.) http://www.cert.hki-online.de/ to see if and when a replacement of your masonry heater insert or an upgrade of the system is required.
If the appliance has no type plate, the manufacturer can provide information, or your chimney sweep
can help.If the insert was put into operation after 22 March 2010, it already meets the requirements of the revised 1st BImSchV and can be used without restrictions and for an unlimited period of time.
The manufacturer’s declaration also specifies the replacement deadline.
- I have an old tiled stove – what should I expect?
- You can relax – the process is straightforward and quick.
- Choose one of our more than 1,000 partner craftsmen across Germany using our craftsman search and arrange an appointment.
- The craftsman will inspect your system and plan the replacement together with you.
- The exchange itself is simple and can often be completed within just a few hours.
- Since the stove casing remains in place and only the insert is replaced, the upgrade is cost-effective and efficient – a new appliance also consumes less fuel.
- With a low-emission insert from BRUNNER, your beloved masonry heater will be ready for the decades to come.
- How do I know if my system needs to be renewed?
- Using the type plate, which every stove, fireplace or wood-burning insert should have, you can check the type and model of your unit.
- The HKI (German Association of Home, Heating and Kitchen Technology e.V.) provides a device list on its website where you can check whether a tiled stove replacement or a renewal of your system is necessary.
- If your unit does not have a type plate, contact the manufacturer directly. They will be happy to provide information about your device.
- Your chimney sweep can also be very helpful here, as they can check the emission values of your system (limits: 0.15 g / cubic meter, carbon monoxide: 4 g / cubic meter).
- Which stoves have to be replaced and by when?
- Commissioned up to and including 31/12/1974: replacement required by 31/12/2014 at the latest
- Commissioned between 1975 and 1984: replacement required by 31/12/2017 at the latest
- Commissioned between 1985 and 1994: replacement required by 31/12/2020 at the latest
- Commissioned between 1995 and 2010: replacement required by 31/12/2024 at the latest
- What is the legally required replacement of stoves about?
- The law requires the decommissioning of older stoves and wood-burning inserts if they do not meet the emission limits of the 1st Federal Immission Control Ordinance (1. BImSchV).
- The reason is the higher particulate and carbon monoxide emissions from older heating systems.
- Newer systems installed between 1995 and 2010 that do not meet the limits must also be retrofitted.
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