The diagrams below illustrate two processes involved in production of heat for the house. The first diagram shows the pellet boiler whilst the second demonstrates the stages involved in a pellet stove.
In the pellet boiler, wood pellets are collected and deposited into the furnace where burning takes place to produce heat. As cold water passes across the furnace, it boils up and then proceeds through the water pipes connected to various sections of the building. This way, the room temperatures go up to the expected levels.
On the other hand, the pellet stove produces heat by combusting the wood pellets that have been delivered though the fuel hopper into the combustion chamber. It burns up to produce hot air which escapes through the combustion pan thus providing the required warmth for the building.
In this pellet stove system water is not required as is the case for the pellet boiler. Each of these systems have an ash receptacle for the burnt wood. Additionally, the stove pellet has an exhaust duct that allows smoke to escape into the air.