ATMOS DC25GSP 25 kW Wood and Pellet Combination Boiler

2026-03-13T12:25:42+01:00

Vendor: Atmos
Type: Combi boiler
Price: 9869.00

ATMOS DC25GSP Wood and Pellet Boiler – efficient combination boiler with 25 kW

The ATMOS DC25GSP is a modern combination boiler for burning firewood and wood pellets. The heating boiler combines the efficiency of a wood gasification boiler with the convenience of an automatic pellet burner. This allows flexible switching between manual wood operation and automatic pellet operation.

With a wood output of 25 kW, the boiler is particularly suitable for single-family homes and larger residential buildings. The combination of wood gasification and pellet technology enables reliable and economical heat supply.

Highlights and Advantages

⭐ Combination boiler for firewood and wood pellets in one heating system

⭐ Heating output up to 25 kW for single-family homes and larger buildings

⭐ Automatic pellet burner start possible after the wood has burned out

⭐ High efficiency of over 92 % for efficient operation

⭐ Boiler class 5 according to EN 303-5 for modern biomass heating systems

Application Area & Target Audience

The ATMOS DC25GSP is suitable for various heating systems in residential areas and is frequently used for:

Single-family homes

Two-family homes

Renovations of existing heating systems

New builds with biomass heating

Heating systems with buffer storage

Due to the combination of wood and pellet operation, the heating boiler can be used flexibly. Firewood is manually refilled, while pellets can be fed automatically.

Advantages in Everyday Use

The combination boiler enables convenient use of two fuels. When heating with wood, the boiler operates as an efficient wood gasification boiler. As soon as the wood has burned out, the pellet burner can start automatically and continue the heating operation.

This keeps the heating system reliably in operation even when no wood is refilled. This increases comfort and reduces the manual effort required for heating.

Technology & Equipment

The ATMOS DC25GSP features a robust steel construction with a ceramic combustion chamber. Combustion is regulated via multiple thermostats and control components.

Boiler thermostat for output regulation

Flue gas thermostat for controlling the induced draft fan

Safety thermostat (STB) against overheating

Servo flap for automatic air regulation

Slot for electronic heating control

The air supply and combustion are automatically adjusted to the fuel used, ensuring stable and efficient operation.

Efficiency & Environment

The ATMOS DC25GSP achieves an efficiency of approximately 92.5 % in wood operation. In pellet operation, the efficiency is around 92.8 %. This allows particularly efficient use of the fuel.

The boiler meets the requirements of boiler class 5 according to EN 303-5 and complies with modern emission standards for biomass heating systems. :contentReference[oaicite:1]{index=1}

Compatibility & System Integration

The combination boiler is typically installed together with a buffer storage tank. This allows the generated heat to be stored efficiently and distributed evenly throughout the building.

The ATMOS DC25GSP can be integrated into various heating systems:

Buffer storage

Radiator heating systems

Underfloor heating systems

Domestic hot water preparation

Technical Data

Manufacturer | ATMOS
Model | DC25GSP
Product Type | Wood and Pellet Combination Boiler
Wood Output | 25 kW
Pellet Output | 6 – 20 kW
Boiler Efficiency Wood | 92.5 %
Boiler Efficiency Pellet | 92.8 %
Energy Efficiency Class | A+
Boiler Class | 5 according to EN 303-5
Heating Surface | 4.1 m²
Fuel Chamber Volume | 120 dm³
Max. Working Pressure Water | 250 kPa
Boiler Weight | 659 kg
Flue Gas Connection | 150 / 152 mm
Electrical Connection | 230 V / 50 Hz
Protection Class | IP20
Required Return Temperature | 65 °C
Operating Temperature | 80 – 90 °C

Accessories & System Recommendations

For efficient and safe operation, combination with suitable system components such as buffer storage, return temperature elevation, and safety groups is recommended.

Suitable System Components

Buffer Storage

Return Temperature Elevation

Safety Groups

Pellet Burner

Heating Controls

Installation and Safety Instructions

Installation must only be carried out by a qualified heating contractor. National regulations as well as the manufacturer's installation and operating instructions must be observed.

FAQ

Can the ATMOS DC25GSP burn wood and pellets?

Yes, the combination boiler is designed for firewood and wood pellets and can switch between both fuels.

What is the heating output?

In wood operation, the output is 25 kW. In pellet operation, the output range is between 6 and 20 kW.

Is a buffer storage tank necessary?

A buffer storage tank is recommended for efficient operation.

Which fuels are approved?

Dry firewood with a residual moisture content of approximately 12–20% and wood pellets with a diameter of 6–8 mm are to be used.

Does the pellet burner start automatically?

The pellet burner can start automatically as soon as the loaded wood has burned out and heat is still required.

What power supply does the boiler require?

The combination boiler requires a mains voltage of 230 V at 50 Hz.

Download

Operating Instructions

Supplement to Operating Instructions

Exploded View Drawing

Combination Boiler Brochure

Pellet Conformity Declaration

👉 Order commissioning service now!
With the "Commissioning by ATMOS" service, you ensure that your boiler is optimally set up and all technical requirements are met.

Further information on the process, requirements, and services can be found in our article on [ATMOS Commissioning].