SL 50/150 Biomass Boiler

A combination of high heat output, optimum combustion and easy maintenance. For wood chips or pellets

Linder & Sommerauer: SL 50/150 Biomass Boiler

The SL 50/150 series combines impressively high heat output, optimum combustion levels, total simplicity of use and straightforward maintenance.

The SL 50/150 series of biomass boilers

The range is capable of burning wood chips or wood pellets and can achieve heat outputs of 50 to 150kW from a single unit. Up to 6 multiple units can be combined in a cascade up to 900kW. 

Every single Lindner and Sommerauer boiler comes with a 5-year warranty that covers all moving parts and electronic controls. 

Parts guide to an L and S biomass boiler

Total Efficiency

We only supply the finest biomass boilers which is why we are proud to bring Lindner and Sommerauer boilers to our customers. They offer some of the highest efficiencies on the market with rapid recovery rates, thanks to innovative steel heat exchangers. 

You can expect perfect combustion in the SL 50/150 series, at gasification temperatures in excess of 1,200°C.

Wood Chip Fuel Delivery Systems

A single agitator 6m in length

Opt for a single agitator of up to 6m in length or multiple agitators on a single unit. Being able to deliver wood chips in such a manner allows you to construct large stores, making bulk buying cost-effective and contract chipping an option.

Wood chip fuel delivery system

What’s more, these delivery systems can be fitted to the left or right side of the boiler, allowing total flexibility in the layout and design of your plant room.

Fuel delivery to a plant room - 01Fuel delivery to a plant room - 02

Fuel delivery to a plant room - 03

This system also comes with a two-piece auger channel (available in lengths up to 15m) and a separate lid for ease of maintenance.

Two-piece auger channel

The auger is one solid piece to allow maximum strength and no points of weakness. This means your fuel store can be located underground, in a garage or outbuilding up to 15m away, whatever suits your project and budget the best.

Wood Pellet Fuel Delivery Systems

Wood pellet fuel delivery systems

For total simplicity, wood pellets can be blown into your fuel store via a vacuum tube. Ask us about fuel store solutions, we can provide plenty of ideas and options.

Fuel store solution

If you have any questions about the best way to specify fuel delivery and storage systems, please don’t hesitate to get in touch with us. 


Steel heat exchanger

The four rows of vertical cylinders in the steel heat exchanger contain sprung, moving turbulators which operate during the cleaning cycle to prevent the buildup of deposits on the heat exchanger surface, ensuring maximum heat transfer and reduced efficiency loss. 

Easy to Use

Your SL 50/150 biomass boiler comes with an electronic touch screen control panel fitted as standard.

Touch screen control for biomass boilers

This sleekly designed, modern interface allows you complete control over timers, thermostats and other aspects of the biomass boiler’s controls.  

Thermostat control via touch screen

Safe and Reliable 

Direct drive gear box

When you choose Lindner and Sommerauer, you know you’re choosing safety, durability and reliability. The bevelled, direct drive gear boxes are designed with silicon carbide-coated ball bearings and the system features no chains that could break or snap. What’s more, they all come with a 5 year warranty as standard.

Burk back protection

The auger motor drive closes if the system shuts down, providing protection against burn back. And the firebox is designed with durable silicon carbide tiles that offer significantly higher resistance to wear than fire bricks. 

Auger sensor

Finally, the discharge auger control sensor prevents the agitator disc rotating when not required to minimise energy use and power consumption. 

Low Ash Volumes

The amount of ash produced to the volume of fuel is around 5%. What little ash there is gets transferred into large ash bins that are easy to remove.

Ash bin for biomass boiler

The ash generated by your biomass boiler is useful as a fertiliser due to high levels of nitrates.

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SL 50/150 Biomass Boiler System







Maximum Heat Output kW 50 65 80 110 150
Minimum Heat Output kW 12.4 12.4 21.5 23.7 41.9
Max Combustion Efficiency % 91.9 93.1 91.7 91.3 91.8
Min Combustion Efficiency % 92.1 93.5 93.0 93.7 93.8
Width mm 770 770 870 870 1,050
Depth mm 1,050 1,050 1,265 1,265 1,465
Height mm 1,430 1,530 1,520 1,620 1,810
Flow & Return Diameter


40 40 40 40 40
Flue Connection Diameter mm 180 200 200 200 250
Flue Connection Height mm 650 650 650 650 650
Boiler Weight (Assembled) kg 675 740 920 980 1,405
Auger Weight kg 82 82 83 83 85
Water Content kg 110 116 120 190 340
Power Consumption A/V 16/400 16/400 16/400 16/400 16/400



What storage facilities are needed for the fuel?

We can supply a range of solutions from bespoke wood chip and wood pellet fuel stores, to prefabricated systems to integrated storage solutions fitted as part of the boiler.

How Big Should a Fuel Store Be?

This depends on the size and use of the boiler, but as a guide, the fuel store should be sized on a fuel consumption that requires around 3-4 fillings per year, and is designed to take a ‘full load’ from the supplier – this will always be the most cost- effective fuel supply available.

What are the auto feed options for your boilers?

We have a range of fuel delivery systems and different sizes of fuel stores, which will auger or vacuum feed the fuel into the boiler.​

Can storage units for the boiler go underground?

Yes they can. We can supply 4-6 tonne underground fuel stores.​

Fuel Storage

What storage facilities are needed for the fuel?

Ask us about our storage solutions. From wood chip stores to prefabricated systems and integrated storage ideas, we can help you to add these to your plan.

How Big Should a Fuel Store Be?

Depending on the size and usage of your boiler, we recommend building storage that only requires refilling three to four times a year. You need an area that can take a ‘full load’ from the supplier to ensure you are getting the most cost-effective option.

What are the auto feed options for your boilers?

We offer a range of delivery systems and different sized fuel stores, which can auger or vacuum-feed fuel into your boiler.

Can storage units for the boiler go underground?

Absolutely. We supply four to six tonne underground stores.