Disadvantages of biomass wood pellet boilers:
- Pellet fuel is bulkier than most fossil fuels
- Basic wood pellet boilers require regular cleaning with the heat exchanger tubes needing to be brushed clean (usually by the owner) every 1-2 weeks during the heating season to maintain efficiency. More advanced pellet boiler systems have automatic cleaning systems
- Pellet boilers contain ash bins which need to be cleaned occasionally.

