How Boilers Work

A boiler is a form of heating system that can be found in many homes and businesses. Boilers have been around for many decades and have proven to be a good choice for heating needs. A boiler is a piece of machinery which uses water to transfer heat from a fuel source. Such fuel sources as oil and gas are used to create the heat and transfer the water to steam which will help heat the home. it is important for home owners to understand exactly how a boiler works so they can become aware of problems if they arise. Below is a simple explanation of how a boiler works.

Overall Operation

As we mentioned above, a boiler contains water which is used to heat the home. the fuel source of the unit will help create the heat by turning the water to steam and the piping the steam through the home. This type of system will eventually turn the steam back to water and then start the process once again. The steam will return and then start the process over and this is called a closed system. If a unit does not return the condensation then it is called an open system

Firetube Boiler

One type of boiler is a firetube system. This system will have fire or a hot gas in the inside of the tubes of the boiler shell. These tubes are surrounded by water and the tubes will be arranged so that the gases inside can pass through as many as four times before they pass out of the stack. The system will expose the heat transfer surface at the water and this type of boiler is found in 80% of boilers that are in use today.

Packaged Boiler

A packaged boiler is a subtype of a Firetube boiler. This type of unit contains the fuel burning equipment as well as mechanical draft, automatic controls and accessories. The unit will work automatically and needs very little care.


A watertube system is another type of boiler unit. This unit has fire or hot gas as well but these items are directed to and around the outside of the tubes instead of the inside. A watertube boiler has at least two drums and is shaped like a rectangle. This unit will separate the steam and water in the top of the drum and the bottom will collect sludge from the unit.

Other Designs

There are also other designs of boilers available on the market which can be adapted and configured to meet the home owner’s needs. To find out more about boiler systems and what will work for your home simply contact your local HVAC dealer to get started!