UNDERFEED PRINCIPLE FOR DRY FUELS - water content up to 35%

While the USF-S series is designed for low outputs, the USF-W series underfeed wood-fuel boilers is designed for outputs of 250 to 1000 kW. 


Quality is a priority at ENDRESS

The highest of demands form the backbone of our work, be it in development, planning, production or maintenance. ENDRESS wood-fuel boilers are tailored to individual needs and are subject to stringent quality assurance standards. When it comes to the production of first class wood-fuel boilers, we accept no compromise. 

✔ Made in Germany

✔ Industrial standard

✔ Fuel class 4-7


Heat exchanger cleaning

The automatic heat exchanger cleaning saves material and ensures a consistently high level of boiler efficiency and long cleaning intervals. The recumbent 3-way pipe heat exchanger offers a generously proportioned water capacity.

Underfeed combustion chamber

The combustion retort is a 15 mm thick steel construction with completely automatic ash removal and a standard ash container for convenient disposal. Radiant curved structure made of individual stone segments and variable flame passage made from high-temperature ceramic cement. A 4-sided vented underfeed combustion chamber ensures efficient and clean combustion. Durable boiler housing made from high quality materials. 

Grate bars

The grate bars of the underfeed retort are made from high-temperature-resistant cast stainless steel with a chrome content of 27%, guaranteeing a long service life. 

Automatic ignition

High level of convenience thanks to optional, temperature-controlled ignition fan for automatic ignition of the fuels. 


Screw stoker and ash removal unit are driven by high quality geared motors made in Germany.

All from a single source

Fuel feeding systems 

All from a single source. We have the perfect, individual solution to feed in your fuel.

Fine dust filter

In-house developed innovative and highly effectively filter technology.

Control systems 

The intelligent Maxi E-Compact Lambdatronic control assures perfect combustion of your fuel.

Still unsure or perhaps you have already found the right firing technology to suit your needs?

Get in touch and let our experts provide you with individual advice according to your wood firing requirements.


Or simply pop in for a visit!
And get to know the system that meets your personal requirements to a tee.