Defro Firewood Plus 12 kW natural draft boiler logs

2025-04-16T12:24:18+02:00

Vendor: Defro
Type: Solid fuel boiler
Price: 2329.00

The Defro Firewood Plus 12 kW This is a modern, high-efficiency, natural-draft wood-burning boiler with a robust steel construction. Thanks to electronic primary air control and an integrated safety heat exchanger, the wood gasifier is ideally suited for new or existing single-family homes.

Highlights/Advantages

⭐ High efficiency of 92.4% – efficient fuel use and reduced heating costs
⭐ Energy efficiency class A+ – future-proof and environmentally conscious heating technology
⭐ Integrated safety heat exchanger – suitable for closed heating systems
⭐ Electronic primary air control – comfortable and precise combustion control
⭐ Multiple connections to the chimney are possible – flexible integration into existing buildings

Detailed description

Area of ​​application & Target audience

The Defro Firewood Plus 12 kW is a natural draft boiler for burning logs (hardwood, residual moisture 12–20%). With its nominal output of 12 kW, it is particularly suitable for single-family homes as well as smaller existing or renovated buildings with manual heating operation.

Thanks to its compact design and the secondary air adjustable on both sides, placement close to a wall is also easily possible.

Everyday benefits

The classic natural draft boiler is technically enhanced by the electronic flue gas regulator. The electronic control system automatically regulates the primary air supply and can also control the boiler circulation pump and an optional induced draft fan.

The large loading doors allow for convenient loading of logs up to 290 mm in length. An integrated sight glass allows visual monitoring of the gasifier flame.

Technology & equipment

The boiler body is made of certified quality steel and is designed for a long service life. A safety heat exchanger is integrated at the factory, allowing the boiler to be operated in closed systems without the need for a double thermal relief valve.

The boiler is suitable for multiple connections to the same chimney. The required delivery pressure is 0.16 mbar.

Efficiency & Environment

With a standard efficiency of 92.4%, the Defro Firewood Plus 12 kW achieves energy efficiency class A+. The increased heat recovery from the exhaust gases ensures particularly economical fuel use.

The recommended minimum buffer storage capacity is 600 liters to optimize operation and emission values.

compatibility & System integration

The natural draft wood gasifier has 1½" (IG) internal thread flow and return connections. The flue gas connection is Ø 159 mm.

The power supply is provided via 230 V/50 Hz for the electronic control.

Suitable components such as:

Buffer storage

Thermal safety device

Boiler circuit sets

Security groups

You can find them in the heating technology section on gemashop.de.

Technical data

feature | Value
Manufacturer | DEFRO
Model | Firewood Plus 12
Product type | Natural draft boiler
Rated power | 12 kW
fuel | Firewood (hardwood 12–20%)
efficiency | 92.4%
Energy efficiency class | A+
boiler weight | 311 kg
Exhaust gas temperature | 124 °C
Exhaust gas mass flow | 10.5 g/s
CO₂ content | 12.3%
Required delivery pressure | 0.16 mbar
Exhaust connection | Ø 159 mm
Flow/Return | 1½" internal thread
Flow temperature min./max. | 75/90 °C
Minimum return temperature | 65 °C
Minimum buffer capacity | 600 l
power supply | 230 V/50 Hz
Dimensions (W x D x H) | 480 x 555 x 1210 mm

Scope of delivery

Defro Firewood Plus 12 kW natural draft boiler

Analog boiler thermometer

Electronic fire draft regulator

Chain for the fire regulator

Short-circuit valve

Vertical grate insert

Wirbulators

Cleaning tool

Operating and assembly instructions

Assembly & Safety instructions

Installation and commissioning must be carried out exclusively by a qualified specialist company.

For proper operation, a sufficiently sized buffer storage tank must be provided. The applicable national regulations, in particular those concerning the exhaust system and hydraulic integration, must be observed.

FAQ

1. For which buildings is the Defro Firewood Plus 12 kW suitable?
It is suitable for single-family homes and smaller buildings with a heat demand in the range of 12 kW.

2. Which fuel may be used?
Firewood (hardwood) with a residual moisture content of 12–20%.

3. Is operation in a closed system possible?
Yes, thanks to the integrated safety heat exchanger, operation in a closed heating system is permitted.

4. Is a buffer storage tank required?
Yes, the recommended minimum capacity is 600 liters.

5. Can the boiler be operated with an induced draft fan?
Yes, an optional induced draft fan can be controlled via the electronic control system.

6. What log length is suitable?
For the 12 kW version, the recommended log length is 250–290 mm.

Conclusion

The Defro Firewood Plus 12 kW is an efficient and robustly built natural-draft wood gasification boiler with modern control technology. A reliable solution for economical heating with firewood.