The following diagrams demonstrate how a pellet stove and boiler use wooden pellets to combust air and boil water to generate heat for the house.
Overall, the pellet boiler uses hot water to distribute heat throughout the house, by exchanging heat energy with the surrounding cold air. On the other hand, the pellet stove uses a combustion air fan to distribute heat energy in the house.
Cold water is pumped through a furnace in the pellet boiler. Wooden pellets are put in the fuel hopper and passed to the furnace. As they burn, they generate heat that heats the cold water in the pipes passing through the furnace. As the hot water passes through the rooms, it heats the surrounding air by heat energy exchange.
In contrast, the pellet stove has a combustion chamber and fan. The wooden pellets are burnt in the combustion chamber generating heat energy that heats the air in the chamber. Through the control mechanism and combustion fan, hot air is fanned to the respective rooms, heating the house. Comparatively, both stove and boiler are fitted with chimneys to allow smoke to flow out and ash pan to collect ash produced during burning.