Kalorina Serie 23 fixed grateClass 3
151–1162 kW
Kalorina Serie 23 fixed grate — Front view
High-output biomass boiler with fixed grate featuring a two-stage combustion principle. Optimised for fuels with high moisture content (up to 35%) and high ash content (up to 7%). Ideal for sawmills, forestry companies, agricultural holdings and district heating networks.
Two-stage combustion principle with regulated primary and secondary air
Manufacturer-certified fuels
Compliant with European EN ISO 17225 standards — performance guaranteed by the original technical sheet.
Wood chips
Shredded wood chips, granulometry P16S to P31S. Cost-effective solution for large surfaces and automated silos.
Wood pellets
Cylindrical compressed wood pellets, Ø6 to 8 mm, moisture < 10%. Standard high energy density fuel.
Log wood
Dry log wood, length 33 to 50 cm, moisture < 25%. Manual loading, autonomy depending on the firebox.
Cereals / Agro-pellets
Compressed cereal blends and agricultural residues. Circular solution for farms.
Specifications according to the manufacturer's technical sheet. Using non-compliant fuels voids the warranty and may shorten the boiler's lifespan.
Kalorina Serie 23 fixed grate: grants
In Germany, replacing a heating system with a biomass boiler (pellets, logs, wood chips) in an existing residential building is subsidised by KfW (programme 458, Federal Funding for Efficient Buildings).
KfW 458 — heating grant for private individuals (BEG EM)
Base grant of 30 % of eligible costs, plus bonuses depending on the situation (climate speed, household income); up to 70 %, or 80 % with the income bonus. Eligible costs capped at €28,000 for a single-family house.
- EXISTING residential building; apply to KfW BEFORE work starts
- Supply or service contract signed with a condition precedent or subsequent
- Climate speed bonus (16 %) when replacing a gas or biomass heating system at least 20 years old; it decreases from 01/02/2027
- Income bonus (40, 30 or 10 %) for owner-occupiers depending on taxable household income
Information checked on October 14, 2026.
