The Biomass Boiler is a system boiler that works in the same way as a conventional gas boiler, except that it uses wood pellets for fuel rather than gas. The boiler automatically fires when the heating control, such as a room thermostat, signals a heating requirement, and pellets are released into the combustion chamber. When the pellets in the combustion chamber are burning evenly and the property reaches the required temperature, the boiler automatically switches to modulation mode. That means it turns itself down to as little as 30% output which saves fuel and matches the heat output with the required room temperature. Pellets are drip-fed automatically into the combustion chamber when they are needed. A light appears on the control panel when the fuel supply in the hopper needs to be replenished.