Kalorina Serie 21AClass 3
23–78 kW
Kalorina 2103 — 360° rotation
Natural draught wood boiler with an excellent price-quality ratio. Used in single-family and two-family homes, farms and small commercial enterprises.
Natural draught combustion system
Available models(5 variants)
Dimensions and architecture
Front view, side view with silo, top view — from the manufacturer's technical sheet.
Schema extracted from the official manufacturer's technical sheet. All dimensions (R, S, K, H, N, C, P, B, L, A, O, Q) are detailed in the full PDF.
Manufacturer-certified fuels
Compliant with European EN ISO 17225 standards — performance guaranteed by the original technical sheet.
Log wood
Dry log wood, length 33 to 50 cm, moisture < 25%. Manual loading, autonomy depending on the firebox.
Specifications according to the manufacturer's technical sheet. Using non-compliant fuels voids the warranty and may shorten the boiler's lifespan.
Kalorina Serie 21: 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.
