Wood Boiler Information
Outside Wood Burners

There are many different brands of outside wood burners and its important for you to shop brands and make the best investment.

There are two categories of outside wood burners—Open Systems and Closed Systems.

An open system is basically a round firebox with a round shaped pot of water around the firebox. The system is vented through the roof to the air, which means more oxygen in the water which causes rust. There are water treatments to counteract this reaction. Open systems need minimum licensing, are simple to install and work well.

A closed system is not vented to the air. It has an expansion tank that absorbs the expansion of heated water. Oxygen is removed from the water with an air separator. Closed systems don’t have the corrosion or water maintenance issues of open systems.

Closed systems will NOT explode. No company would be in business for long if their products were dangerous. Closed systems have more protections/safeties than any closed system.

Closed systems have a longer life, cleaner water and longer lasting components like pumps and valves. However, closed systems sometimes require licensed professionals to install them and do include more components that raise the price.


910 N M-37
Baldwin, MI 49304
(231) 745-6110