A complete guide for Firebull hot air stove owners. Learn how to operate, clean the glass, and maintain your stove for Firebull Mini and S6–S18 models.

Firebull Hot Air Stoves: Installation and Operating Manual

Intended Use and Operating Principle
Important Pre-Installation Warnings
Efficient Dual-Chamber Combustion
Flammability of Building Materials and Safety Distances
Assembly and Installation Instructions
Operation and Use
How to Light the Fire Correctly
Adding Fuel (Safe Procedure)
Maintenance and Cleaning
Power Regulation (Damper Positions)
Regular Inspection and Service
Troubleshooting (FAQ)
Warranty and Service Conditions
Service Contact
Warranty Exclusions
How to File a Claim
Ecology and Disposal

This manual is intended for the installation, operation, and maintenance of the Firebull wood stove series. The design and operating principles are identical for the entire model line.

Supported Models:

Firebull Mini
Firebull S6, S8, S10, S12, S14, S16, S18

1. Intended Use and Operating Principle

Firebull hot air stoves are designed for local heating and supplemental heating in a wide range of spaces, including:

Residential spaces: Family houses, cottages, cabins, clubhouses.
Commercial and public buildings: Restaurants, cultural halls, greenhouses.
Industrial spaces: Production halls, warehouses, workshops, or construction site facilities.

The stoves are intended for use in standard environments. They must not be exposed to direct weather conditions and are not permitted for use in potentially explosive atmospheres or in the presence of volatile substances.

Efficient Heat Transfer Without a Fan

The unique design of Firebull stoves utilizes not only surface radiation for heating but primarily natural air circulation. The stove casing consists of a system of tubes that function as an internal heat exchanger.

Intake: Cold air near the floor is naturally drawn into the lower section of the tubes.
Heating: As it passes through the tubes around the combustion chamber, the air heats up rapidly.
Distribution: Hot air exits through the upper section of the tubes and spontaneously mixes with the air in the room.

Main advantages of this system:

Silent operation: Rapid air mixing occurs without a noisy fan.
Energy independence: The system does not require electricity, so there is no risk of the stove overheating during a power outage.
Reduced dust: Circulation is natural and does not cause excessive dust swirling like forced ventilation.

IMPORTANT NOTICE: The surface of the stove and its components reach high temperatures during operation. All handling (loading fuel, regulation) must be performed exclusively using heat-resistant gloves to prevent the risk of burns.

2. Important Pre-Installation Warnings

Read this manual thoroughly before installing the appliance. It contains key information for safe and efficient operation. Keep the manual near the stove for future reference.

Inspection Upon Receipt

Upon delivery, check the packaging, integrity, and completeness of the contents. In case of any doubts, do not use the device and contact the supplier immediately.

Safety Regulations

Liability: Installation must comply with the current standards in the country of use and the manufacturer's instructions. The manufacturer bears no responsibility for injury or property damage resulting from incorrect installation.
Operation: The stove may only be operated by persons over 18 years of age who have demonstrably familiarized themselves with the manual.
Children and Pets: Leaving children or pets unattended near the stove is strictly prohibited.
Distances and Protection: Maintain the specified safe clearance distances from combustible materials. If protective floor pads or screens are part of the installation, never remove them.
Environmental Changes: If a change occurs in the room that could lead to a risk of fire or explosion (e.g., working with volatile substances), take the stove out of operation in a timely manner.

Operation and Maintenance

Prohibition of Modifications: It is forbidden to make any unauthorized changes to the device.
Repairs: In the event of a malfunction, do not attempt to repair it yourself. Always contact a qualified professional.
Spare Parts: Use only original spare parts supplied by the manufacturer.
Do Not Overload the Stove: Adhere to the recommended heat output. Overloading can lead to damage to the refractory plates inside the stove (e.g., due to heavy impacts from logs or excessive heat).

3. Efficient Dual-Chamber Combustion

Firebull stoves utilize a dual-chamber combustion system. To ensure proper functionality and maximum efficiency, three basic conditions must be met:

High-Quality Fuel: Use exclusively dry wood with a maximum moisture content of 20%. This is typically achieved by seasoning wood under a shelter for approximately 2 years.
Operating Temperature: To activate efficient secondary combustion, a temperature of 350–600 °C must be reached within the combustion chamber.
Air Supply: Ensure an adequate supply of primary and secondary air (settings may vary depending on the individual draught of your chimney).

4. Flammability of Materials and Safety Distances

When installing Firebull stoves, it is essential to take into account the flammability class of the surrounding materials (floors, walls, furniture). The table below categorizes common building materials into flammability classes:

Flammability Class	Characteristics	Examples
A – Non-combustible	Does not burn	Granite, sandstone, concrete, bricks, ceramic tiles
B – Hard to ignite	Very low fire contribution	Akumin, Heraklit, Itaver
C1 – Heavy flame spread	Burns slowly	Hardwood (oak, beech), plywood, umakart
C2 – Medium flammability	Standard burning	Chipboard, cork, rubber
C3 – Easily flammable	Burns rapidly	Fiberboard, polystyrene, soft wood (conifers)

5. Assembly and Installation Instructions

During the installation of Firebull stoves, all local, national, and European standards must be observed (specifically in accordance with EN 13240 and relevant regional building codes).

Flooring and Load-Bearing Capacity

The stove must be placed on a non-combustible floor with adequate load-bearing capacity. If the existing floor does not meet the requirements, a load-distributing plate must be used.

Protective Floor Pad (when placed on combustible materials): If the stove is installed on a combustible floor, it must be equipped with a heat-resistant and mechanically durable pad that exceeds the stove's footprint by at least:

Front: 600 mm
Sides: 400 mm

Safe Clearance Distances

From combustible materials: A minimum of 800 mm in all directions.
Protective shielding: If the 800 mm distance cannot be maintained, a fire-resistant shield must be used. This applies especially in cases where the surface temperature of combustible walls or furniture could exceed 100 °C.

Chimney Connection

Chimney Draught: The minimum required draught is 12 Pa.
Professional Connection: The connection may only be performed by a professionally qualified person with the approval of a certified chimney sweep or technician.
Shared Flue Prohibition: The stove is not intended for connection to a shared chimney flue with another appliance.

Flue Gas Ducting Installation:

The flue pipe must be as short as possible and must not taper toward the chimney.
Pipes longer than 2 m must be firmly anchored to the masonry (e.g., using a bracket).
Individual components must fit together tightly. Important: The lower pipe is inserted into the higher one (so-called "along the flow of flue gases") to prevent flue gas leakage into the room.
Ensure access for cleaning the flue pipe and the chimney sweep door.

Air Supply (Ventilation)

For proper combustion, Firebull stoves require a sufficient supply of oxygen.

Required Volume: Ensure an air supply of approximately 200 m³/h in the enclosed space.
Air Sources: In standard buildings, air leakage through windows and doors is usually sufficient.
Warning: We do not recommend using extractor hoods (range hoods) or other air-exhausting devices in the same room as the stove. These can cause a drop in chimney draught and result in flue gases backing up into the room.
Post-Inactivity Check: If the stove has not been used for an extended period, always check before lighting a fire to ensure the flue pipes and chimney are not blocked (e.g., by soot or cobwebs).

6. Stove Operation and Usage

Commissioning (Curing the Paint)

The surface of Firebull stoves is treated with a special thermal coating. During the first firing, this coating undergoes a final curing process, which is accompanied by:

Light smoking from the stove surface.
A characteristic odor.

Recommendation: Perform the first firing before the start of the heating season. Ensure intensive ventilation (draft) and temporarily move pets (especially birds and more sensitive animals) out of the room.

Fuel: What to Use (and What to Avoid)

Firebull stoves are designed exclusively for firewood.

Suitable Fuel: Dry logs with a diameter of approximately 100 mm. Hardwood (beech, oak, birch, hornbeam) is ideal as it burns longer.
Unsuitable Fuel: Softwood (conifers) burns quickly and causes more soot buildup in the chimney.
Prohibited Fuels: Coal, coke, briquettes, sawdust, waste, liquid fuels, and flammable liquids. The use of gasoline or alcohol for lighting the fire is strictly prohibited!

7. Correct Lighting Procedure

Preparation: Place 2–3 smaller logs on the bottom of the firebox (can be placed on a bed of residual ash). Place paper or an approved firelighter on top, followed by sufficient kindling.
Loading: For the initial lighting, load a larger amount of wood (up to approximately 1/2 of the combustion chamber height). This ensures the chimney heats up quickly and creates the proper draught.
Air Supply: Open the primary air regulators to the maximum position.
Lighting: Immediately close the door after lighting the fire.
Regulation: Once the fuel is burning properly, use the regulators to set a steady, rather dampened combustion.

Warning: Excessive draught or an overabundance of fuel can lead to overheating and permanent damage to the stove. Conversely, low draught (below 12 Pa) causes glass sooting and smoke leakage into the room.

8. Refueling (Safe Procedure)

To prevent smoke from escaping into the room when opening the door, follow this procedure:

Open the Dampers: Open the flue gas damper and the air intake fully for at least 10 seconds.
Pressure Equalization: Open the door only slightly (to a crack) and wait a few seconds for the chimney draught to stabilize.
Opening: Only then open the door completely and add fuel.
Quantity: Add fuel only once the previous load has burned down to a glowing bed of embers. The door must always be easy to close.

How to Control Heat Output

The output of the stove is regulated not only by air intake but primarily by the size of the logs:

Thick logs: Long burn time, smaller flame, lower heat output.
Thin/split logs: Short burn time, large flame, high immediate heat output.

9. Maintenance and Cleaning

How to Keep the Glass Clean

Glass cleanliness depends on the chimney draught as well as the method of operation.

Proper Loading: Place fuel in a single layer as far from the glass as possible. Leave gaps of approximately 10 mm between logs (or eco-briquettes) for airflow.
Heat Self-cleaning: If the glass becomes lightly sooted, open the air regulator in the door. The increased combustion intensity will usually burn off the soot automatically.
Mechanical Cleaning: Perform only when the stove is cold. Use a specialized fireplace glass cleaner, oven cleaner, or dampened newspaper dipped in fine ash.

Ash Removal

Firebull stoves do not have a grate; therefore, do not remove the ash completely.

Ash Bed is Desirable: A remaining layer of ash protects the bottom of the stove and helps maintain the temperature differential necessary for air circulation.
When to Remove: Remove ash only when it reaches the lower edge of the loading opening.
Safety: Remove ash only when cold. Use non-combustible containers with a lid or a specialized ash vacuum. Wood ash is an excellent fertilizer for compost.

10. Power Regulation (Damper Positions)

For proper operation, it is essential to know the positions of the control elements:

Control Element	Open (Maximum)	Closed
Flue Gas Damper	Lever parallel to the flue pipe	Lever perpendicular to the flue pipe
Primary Air (Door)	Lever in a horizontal position	Lever in a vertical position
Secondary Air	Lever in a horizontal position	Lever in a vertical position

Optimal Settings for Maximum Efficiency

During standard operation with a good chimney draught, we recommend the following settings:

Primary Air Damper (in the door): Open to 25%.
Secondary Air Damper: Open to 100%.

11. Regular Inspection and Service

Seals: Regularly inspect the sealing cords on the door and glass. If they are frayed, worn out, or no longer provide a tight seal, replace them.
- Tip: After the first month of operation, check the tightness of the glass holders (the sealing cord tends to "settle" during initial use).
Lubrication: Occasionally lubricate the door hinges and the moving parts of the dampers with a heat-resistant lubricant. Always perform this when the stove is cold.
Chimney: Entrust chimney cleaning to a qualified professional. Keep the flue pipes clear and clean at all times.

12. Troubleshooting (FAQ)

Smoke escapes into the room: Check the chimney draught, the cleanliness of the flue pipes, and ensure that no extractor hood (range hood) is active in the house. If the problem persists, stop heating immediately and ventilate the room!
The stove is overheating: Immediately close all air intakes and the flue gas damper.
Chimney fire: Close all air intakes. Do not use water to extinguish the fire! Call the fire department immediately and have the chimney inspected by a certified chimney sweep after the fire is out.

13. Warranty and Service Conditions

Warranty Period and Manufacturer's Liability

The company Radek Líbal – Firebull provides a warranty for the wood-burning stoves for a period of 36 months from the date of receipt of the product.

The warranty is valid only if all rules for installation, operation, and maintenance specified in this manual are strictly observed.
During the warranty period, the product shall maintain the properties established by technical standards and the data on the production label.
All legal relationships are governed by the Civil Code (Act No. 89/2012 Coll.). Any potential disputes shall be resolved by the District Court in Hradec Králové, Czech Republic.

What the Warranty Covers

The warranty covers the free repair of defects caused by faulty materials or errors in workmanship.

The warranty does not cover:

Normal Wear and Tear: Natural degradation of components caused by standard operation.
Glass: The warranty does not apply to cracked or otherwise mechanically damaged glass.
Unauthorized Modifications: The warranty becomes void if any third party interferes with the construction of the stove without the manufacturer's knowledge.

14. Service Contact

Both warranty and post-warranty service in the Czech Republic are provided directly by the manufacturer. In case of doubt or malfunction, always contact us before attempting to resolve the situation on your own.

Manufacturer and Service Center:

Radek Líbal – Firebull
Lišická 881, Chlumec nad Cidlinou, 503 51, Czech Republic
Tel.: +420 777 332 322
E-mail: info@kamnafirebull.cz

Claim Processing Period: The standard period is 30 days from the date the claim is filed.
International Service: Warranty and post-warranty services are provided by the respective importers or contractually authorized organizations in the given country.

15. Warranty Exclusions (When a Claim Cannot Be Accepted)

The warranty does not cover defects and damage caused by external influences or improper use. Radek Líbal – Firebull bears no responsibility, particularly in the following cases:

Poor Installation and Draught: Errors in flue connection, insufficient or, conversely, excessive chimney draught (not complying with standards).
Incorrect Output Selection: If the stove is undersized for the space (leading to overheating) or oversized (leading to tarring/creosote buildup).
Improper Operation: Overloading the stove (e.g., heating with the door open), using unsuitable fuels, or forceful mechanical damage.
Structural Damage: Burn-through of the deflector or casing deformation due to thermal overload.
External Influences: Chemical exposure during transport, unsuitable storage, contamination by spilled food, or cooling a hot stove with water.
Unauthorized Interventions: Modifications to the firebox, flue gas outlet, or the use of non-original Firebull spare parts.
Neglected Maintenance: Cleaning with unsuitable agents or insufficient care for the appliance.
Force Majeure: Natural disasters (floods, fires, etc.).

16. How to File a Warranty Claim

File a claim with your dealer or directly with the manufacturer. For rapid processing, please have the following ready:

Stove Type and Year of Manufacture: (Found on the rating plate on the back of the stove).
Proof of Purchase: (Invoice).
Evidence of the Defect: (Photo documentation or a description of the fault).

Customer Tip: Before filing a claim, we recommend checking the "Troubleshooting" section. Often, the issue is related to chimney draught or damp wood, which can be resolved without service intervention.

17. Ecology and Disposal

We care about the environment. Please take a responsible approach to waste:

Packaging Materials: All packaging belongs to the "Other – O" category. They are not contaminated with harmful substances. Please submit them for recycling (paper to the blue bin, foil/wrap to the yellow bin).
End-of-Life Stove: At the end of its service life, deliver the product to a scrap yard as metal waste. It consists of material that is nearly 100% recyclable.