A reliable, effective source of heating and hot water is essential for a whole range of different organisations – and commercial boilers are designed to provide exactly this. From keeping school classrooms warm to ensuring there is hot water available on demand in leisure centre changing facilities, these large-scale boilers perform a variety of crucial functions. In this post, we look at how these appliances work, the different varieties available and the increasingly sophisticated features they can have. 

How do commercial boiler systems work?

There are various types of commercial boiler available, and these appliances function in different ways. However, in broad terms, they are pressurised systems which either use electricity or burn fuel in order to heat water that is then used to provide heating and a hot water supply to a building. Depending on the type of system, they may create hot water or steam, which is then circulated via pipes through the commercial facility.

Inside the boiler, the fuel burners or electric coils create heat, which is then transferred to the water via a heat exchanger. A heat exchanger is a component which allows heat energy to be exchanged between two fluids or substances without these substances mixing together. It is this process which creates the hot water or steam that travels through a building’s pipes to the areas where it is needed. This hot water or steam then enters radiators or other heating system components that disperse the warmth, allowing users to keep their premises at the desired temperature.

Commercial boilers that rely on fuel combustion feature a burner, which provides the flames that heat up the water. This burner creates a mixture of oxygen and fuel that produces a consistent, efficient flame. The appliances also typically have a combustion chamber. This is a secure zone where the high-temperature burning of volatile fuels takes place. Often, these chambers are made from heavy duty metals such as cast iron or steel. The boilers also have a heat exchanger. As mentioned previously, this is what facilitates the transfer of heat to the water. Other components of a commercial boiler tend to include system controls and an exhaust stack.

There are various differences between these appliances and the boiler you may have at home, but the main ones are size and power. In general, commercial boilers are designed to be much bigger and more powerful than domestic-scale heating solutions.

How do commercial ​​condensing boilers work?

Condensing boilers incorporate an additional heat exchanger to transfer latent heat from the flue gases to the cooler water entering the boiler, enabling them to produce around 10% more heat for every unit of gas used compared with a standard, non-condensing boiler.

What exactly happens inside a commercial boiler?

A commercial boiler utilises fuel combustion to generate heat, starting with the ignition of fuel by a burner in the combustion chamber. The released thermal energy is transferred to a heat exchanger, where it is absorbed by water or converted into steam. In a water-based system, the heated water circulates through pipes to provide hot water for various applications. In a steam-based system, the generated steam is distributed through pipes to heat radiators or other heat emitters. Controls and safety mechanisms ensure proper operation, while an exhaust system removes combustion gases. Overall, a commercial boiler efficiently produces heat by burning fuel, transferring it to water or steam, and distributing it for heating purposes.

The basic components of commercial boilers

This section will be discussing the components of a commercial boiler.


The burner is the area where the air mixes with your fuel source and combusts.

Heat Exchanger

The heat exchanger allows the heat from the combustion chamber to heat the water in the boiler’s tank.

Combustion Chamber

This is the chamber where the combustion from the burner heats the heat exchanger; this chamber can reach temperatures of several hundred degrees.

Exhaust Stack

The exhaust stack is responsible for removing the combustion gases from the heat exchangers. (This is the reason a cracked heat exchanger is such a serious issue; you want the exhaust gas to go up the stack, not leak into the cabinet.) The gas naturally rises through the vertical shaft to be safely vented outside.


Remote monitoring technology

Commercial boiler technology is developing all the time, and this equipment continues to advance in terms of efficiency, functionality and reliability. One example of this is the fact that it’s now possible to choose appliances that feature remote monitoring systems. For example, at Ideal Heat Solutions, we provide commercial boilers for hire that come complete with a state-of-the-art BMS Two Way Monitoring system. This allows us to oversee boiler performance remotely, meaning we can identify and address any issues that may arise swiftly and effectively. This additional level of expert oversight means that as the user, you can benefit from greater peace of mind and a smoother experience.

How Do Commercial Boilers Work FAQs

How does a commercial heating system work?

A commercial heating system with a boiler operates by using a fuel source, such as natural gas or oil, to generate heat. The boiler heats water or produces steam, which is then circulated through a network of pipes to deliver heat to various areas within the building. The heat is transferred from the boiler to radiators, convectors, or underfloor heating systems, where it is released into the space. The boiler system is controlled by thermostats, ensuring that the temperature is regulated and maintained at the desired level. Commercial boilers are designed to meet the specific heating demands of larger buildings and establishments, providing efficient and reliable heating for commercial spaces.

What is the difference between residential and commercial boilers?

The main difference between residential and commercial boilers lies in their size, capacity, and intended usage. Residential boilers are designed for smaller-scale applications, typically heating individual homes or small apartment buildings. They have lower heat outputs and are more compact in size. In contrast, commercial boilers are built to handle larger heating demands, such as those required for office buildings, hotels, schools, or hospitals. They have higher heat outputs, larger physical dimensions, and are capable of handling higher water or steam flow rates. Commercial boilers often incorporate advanced controls and monitoring systems to meet the specific needs of commercial environments. Additionally, commercial boilers may have additional features, such as multiple heating zones, to provide precise temperature control for different areas within a building.