How Pellet boilers work
A fully controllable, automatic way to heat your home, that burns wood? Pellet boilers work by burning wood pellets in controlled quantities, depending on when and how much heat is required. If someone had a pellet boiler running their heating, generally you would not notice any difference to heating running from an oil or gas boiler.
Pellet boilers can use different methods to get the pellets into the boiler.
Built in pellet hopper
A pellet boiler with a built in hopper will be able to run for a couple of days with a supply of pellets. Wood pellets are available in small or large bags and all that is required is to re-fill the built in hopper a couple of times a week.
Combined pellet storage
These boilers have a larger pellet storage fixed to one side of the boiler and will last much longer before they need filling up again. This is a neat solution that can be installed in a boiler room, without the need for a separate storage area for pellets.
Separate wood pellet storage
Both of the above systems can have a totally automatic pellet feed from a pellet storage area. The area can be a storage room or a storage container which can go in the garden, and can hold a years worth of pellets. The pellets are then sucked through special tubing to the boiler when the boiler needs fuel. The pellet boilers that have a built in hopper are fed the pellets directly from the remote pellet storage. The boilers that have a built on hopper are fed pellets into this hopper as a top-up, which then provides the boiler with pellets when required.
Pellet boilers come in a range of maintenance levels, from those where ash needs removing, the heating surface needs cleaning and pellets need to be loaded to fully automatic models where everything is done, including the removal and compression of ash.
Firing up the wood pellets
When there is a call for heat, some pellets are dropped into the burning dish, and an electric heat element briefly heats the pellet until they ignite (which doesn't take long). When the fire is going, more pellet are dropped in controlled quantities into the fire. When there is no more call for heat, the pellet supply stops and the fire goes out. On fully automatic boilers the burning dish is cleaned, and ash is removed.