Wood Pellet Ash Content: What 0.7% vs 1.2% Really Means
Ash content is the cleanest way to spot A1 vs A2 pellets. Where the ash comes from, why it matters to the burner, and how to test it.
Ash is the incombustible residue left after burning. It sets the certification class, dictates how often the customer empties the ash pan, and drives boiler maintenance cost.
Where ash comes from
Ash originates in the wood itself — mineral content pulled up through the roots — plus bark, soil, and sand picked up during harvest and handling. Cleaner feedstock, lower ash.
A1, A2, and industrial in one line
- A1: ≤ 0.7% — clean stemwood only
- A2: ≤ 1.2% — accepts bark and forest residues
- Industrial (B / I3): ≤ 3.0% — power stations
Why buyers care
A residential pellet stove burning A1 (0.5% ash) generates ~5 kg of ash per tonne. Push that to A2 (1.2%) and the ash pan fills nearly three times as fast — and clinker risk rises with lower ash-melting temperature.
Pellet Industries ships ENplus A1 and industrial biomass pellets worldwide in 15 kg bags, big-bags, and bulk vessel loads.
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