FIREWOOD AND PELLET BOILER

NEW! S2 Dual compact

15 – 20 kW

Integrated particle separator
(electrostatic precipitator)
available as an option

Firewood and pellet boiler

NEW! S2 Dual compact

Two systems perfectly combined

The S2 Dual compact firewood and pellet boiler combines two perfect systems – it meets all the requirements for firewood and pellet fuels in two separate combustion chambers. Highly efficient and convenient – the S2 Dual compact ensures low emissions and low energy costs. The new LTC 5000 control system with 7″ glass touch display offers even more options for controlling the boiler. The swivelling flue pipe connection makes adapting to different types of installation possible, considerably facilitating installation. Optionally, an integrated particle separator ensures even lower emissions and fulfils the highest requirements for environmental friendliness. Proven features such as efficient carbonisation gas extraction, the speed-controlled induced draught fan, long refilling intervals and low power consumption make the S2 Dual compact a solution that is as economical as it is convenient. The S2 Dual compact also offers important advantages when installed in the boiler room: The compact design means that installation is child’s play, even when space is limited.

Pellet unit can be retrofitted at any time

Froling offers a flexible solution for people who may want to use pellets in future: the S2 Turbo comes with a pellet flange as standard, which means that the pellet unit can be retrofitted at any time. This is supplied fully insulated and ready to plug in.

Information/advice

You would like to have further product information or you have general questions regarding our company?

The latest technology

Regelung Lambdatronic 5000

Lambdatronic 5000 controller with 7" glass touch display for even easier operation

Luftgekühlte Füllraumtür

Air-cooled fuel loading chamber

Stellmotor

Servo-motor for automatic control of heating, primary and secondary air

Wassergekühlter Pelletsflansch

Water-cooled pellet flange

Praktische Komfort-Aschelade

Practical, convenient ashcan for simple, dust-free emptying and long emptying intervals

Großvolumiger Pelletsbehälter

Large pellet container with stoker screw and external suction module

Hochwertige Isolierung

High-quality insulation

Wassergekühlter Pelletsbrenner

Water-cooled pellet burner with slide valve for automatic ash removal and cleaning

Großer Füllraum für Halbmeter-Scheite

Large fuel loading chamber for logs up to half a metre long
(up to 56 cm)

Hochtemperatur-Schamottbrennkammer

High-temperature firebrick-lined combustion chamber

Individual controller for the heating system

Lambdatronic 5000 controller

With the new Lambdatronic 5000 boiler controller and the modern 7″ glass touch display, Fröling is moving into the future. The new design is impressive, not only for its intuitive operation but also its numerous new features. The most important
components can be freely selected in the tile overview and information and error messages can be customised. For example, the control system will inform you when the ash box needs to be emptied. This makes operating and running the system even simpler and easier to understand. The intelligent control management enables the almost unlimited integration of heating circuits, storage tanks and hot water tanks.

Advantages

  • Precise combustion control by a Lambda controller using a Lambda probe
  • Connection of heating circuits, water heaters and buffer storage tanks Management systems
  • Integration capability for a solar panel system
  • LED frame for status display with illuminated presence detection
  • Simple & intuitive operation
  • Various SmartHome solutions (e.g. Loxone, Modbus TCP) Remote control from the Living room (room console) or via the Internet (froeling-connect.com)

Keep track of everything with the Froling App

The Froling App allows you to check and control your Froling boiler online from
anywhere, at any time. You can read and modify the main status information and settings easily and conveniently online. You can also specify which status messages you want to be informed about via SMS or e-mail (e.g. when the ash box is to be emptied or in the event of a fault message).
The app is available in the Android Play Store and iOS App Store.

Advantages

  • Simple and intuitive operation of the boiler
  • Status information can be called up and changed within seconds
  • Individual naming of the heating circuits
  • Changes of status are notified directly to the user (e.g. via
    e-mail or push notifications)
  • No additional hardware required (such as an Internet gateway)

 

 

Smart Home

Loxone

Combine your Froling heating system with the Loxone Miniserver and the new Froling Extension and implement individual boiler control on the basis of the single room control of the Loxone Smart Home.

Modbus

Via the Froling modbus interface, the system can be integrated
into a building management system.

Brochures / EU Labels

NEW! S2 Dual compact

Tecnical data

Tecnical data - S2 Dual compact1520
Nominal output[kW]15
Output range - pellet mode[kW]4,4 - 15
Energy rating label (Efficiency label (boiler + controller)A+A+
Weight - firewood boiler / pellet unit[kg]455 / 190
Water capacity - firewood boiler / pellet unit[l]90/15
Fuel loading door dimensions - firewood boiler (width/height)[mm]350/360
Fuel loading chamber capacity - firewood boiler[l]80
Pellet container capacity (automatic feed)[l]40
NEW! S2 Dual compact

Dimensions

Dimensions in mm - S2 Dual compact1520
L1     Length of the boiler (flue gas pipe connection at rear)10701070
L2    Distance from the flue gas pipe top connection to the front face of the boiler915915
L3    Length, pellet unit860860
L4    Length, firewood boiler10001000
B1    Total width including WOS lever11501150
B2   Width, firewood boiler685685
B3   Width, pellet unit315315
B4   Width, boiler10001000
B5   Distance between flue gas pipe connection and side of boiler585585
B6   Distance between flow connection and side of boiler450450
B7    Distance between return connection and side of boiler150150
B8   Distance between safety heat exchanger connection and side of boiler420420
B9   Distance between safety heat exchanger connections6565
B10 Distance between drainage connection and side of boiler890890
H1   Height of boiler13351335
H2   Height of rear connection for the flue gas pipe12301230
H3   Height of the flue gas pipe top connection13851385
H4   Height of hose line connection12551255
H5  Height, safety heat exchanger connection840840
H6  Height, return connection130130
H7   Height, drainage connection125125
H8  Height of connection for flow11251125
Flue gas pipe diameter129129
NEW! S2 Dual compact

Operating and mainten­ance areas

Minimum clearances - S2 Dual compact [mm]15 / 20
A Clearance from insulated door to wall800
B Door swing area500
B1 Clearance from boiler side without pellet unit to wall815
C Clearance from back side to walld400
D Clearance from side of boiler to wall¹500 (200¹)
E Maintenance area above the boiler²500

¹ The heat exchanger for the boiler is accessible for maintenance only from the front
2 Maintenance area for removing the WOS springs upwards

Tecnical documentation

Bedienungsanleitung Kombikessel S2 Dual compact (ESP)
27. August 2025 B2000025 [DE]
Klemmenplan S2 Turbo 15-20 / S2 Dual compact 15-20
23. April 2025 M2900225 [DE]
Montageanleitung Kombikessel S2 Dual compact (ESP)
27. August 2025 M2970025 [DE]
Installation instructions Dual fuel boiler S2 Dual compact (ESP)
7. January 2026 M2970025 [EN]
Manual de instalación Caldera de lena y pélets S2 Dual compact (ESP)
7. January 2026 M2970025 [ES]
Instructions de montage Chaudière mixte S2 Dual compact (ESP)
7. January 2026 M2970025 [FR]
Manuale di installazione Caldaia combinata S2 Dual compact (ESP)
7. January 2026 M2970025 [IT]
Monteringsanvisning Kombinationspanna S2 Dual compact (ESP)
7. January 2026 M2970025 [SV]
Montageanleitung Pelletseinheit für S2 Dual compact (ESP) Anleitung zur Nachrüstung bei bestehendem Scheitholzkessel S2 Turbo (ESP)
27. August 2025 M2990025 [DE]
Installation instructions Pellet unit for S2 Dual compact (ESP) Instructions for retrofitting existing firewood boiler S2 Turbo (ESP)
7. January 2026 M2990025 [EN]
Manual de instalación Unidad de pellets para la S2 Dual compact (ESP) Instrucciones para modernizar la caldera de leña existente S2 Turbo (ESP)
7. January 2026 M2990025 [ES]
Instructions de montage Unité à granulés pour S2 Dual compact (ESP) Instructions pour moderniser la chaudière à bois existante S2 Turbo (ESP)
7. January 2026 M2990025 [FR]
Manuale di installazione Unità pellet per S2 Dual compact (ESP) Istruzioni per l'adeguamento della caldaia a legna esistente S2 Turbo (ESP)
7. January 2026 M2990025 [IT]
Monteringsanvisning Pelletsenhet för S2 Dual compact (ESP) Instruktioner för eftermontering av befintlig vedpanna S2 Turbo (ESP)
7. January 2026 M2990025 [SV]

For you personally

Information & advice

You would like to have further product information or you have general questions regarding our company?

Contact

Fröling Heizkessel- und Behälterbau Ges.m.b.H.
Industriestraße 12 | A – 4710 Grieskirchen

Company

Froling is a pioneer in modern wood heating systems. The Froling signature is on many products from the groundbreaking invention of the firewood boiler with high-temperature combustion, from the wood chip burner with Lambda technology to the development of the internationally acclaimed pellet boiler.

A wide variety of well-known international quality awards underscores the ongoing success of the Austrian family company.

Heating with biomass

Heating with wood is convenient, saves on heating costs, is a secure renewable raw material and is also carbon-neutral