Your Guide To Light Commercial Boiler Installations

Light commercial boiler installations could provide a fantastic new revenue stream for your business. While commercial boilers typically have an output over 70kW, conducting light commercial installation with a total output under 70kW could provide a world of new opportunities for installers looking to expand or refocus their business.

We’ll take a look at what classifies as light commercial work, what qualifications you need to carry out this work and how to make a successful move from domestic to commercial installations. 

What Is Light Commercial Work for Heating Engineers?

When it comes to central heating installations, light commercial work relates to work carried out on smaller-scale commercial properties such as offices or independent shops and restaurants. It can also refer to work being carried out to upgrade or enhance an existing commercial structure. 

Commercial light work involves carrying out a variety of jobs to construct and service these buildings - including installing a suitable heating system that can meet the demands of a small commercial property. 

We’re seeing a rise in the number of small businesses needed to service the growing population. After all, our global population has grown from 2.5 billion in 1950 to 7.9 billion in 2021. As a result, the need for more doctors surgeries, convenience stores and large family homes could provide interesting light commercial opportunities for installers as new building work is needed to support population growth. 

The Difference Between Domestic and Commercial Boiler Installation

Domestic boilers typically have an output under 70kW, whereas commercial boilers should have an output over 70kW. 

Light commercial boilers fall somewhere between the two – typically with an output of between 40-70kW. They are often manufactured specifically to meet the demand of a small-scale commercial property. Light commercial boilers are often energy efficient, easy to control and manage, with the ability to be installed independently or as part of a boiler cascade where higher outputs are required. 

It’s also worth remembering that if a boiler is to be installed in commercial premises, it has to meet the commercial requirements of IGE UP10 and BS6 644 must be adopted, even if the total power output is under 70kW. 

The Benefits Of Light Commercial Work For Installers

Installers are always on the lookout for new opportunities to grow their business, and light commercial installations could be the key! 

For a domestic business, branching out into light commercial projects can provide an income boost amidst economic challenges. By arming yourself with knowledge of all the nuances between domestic and light commercial buildings, as well as the products available, you could successfully diversify your business.

This section of the market could also be a great area for those who don’t want to rely solely on big commercial projects during uncertain and potentially unsettling times. Building services engineers may want to train in light commercial work to diversify away from purely working on large commercial projects and projects within the construction industry. 

The National Federation of Self Employed & Small Businesses has reported an increase of 97,000 private sector businesses since 2015 and two million more since 2000. These statistics show that demand for light commercial projects will continue to be on the increase, providing a steady stream of work for installers. 

Some installers believe light commercial work can be more complicated than domestic installations when, in fact, commercial boilers can be as straightforward to install as their domestic counterparts. Of course, the application may be slightly different, but with some training and research you’ll be well on your way to feeling comfortable installing light commercial boilers. 

What Qualifications Do You Need To Carry Out Light Commercial Work? 

As part of their Domestic Gas Safe Registration, domestic installers can carry out light commercial installations if:

  • An installation has a total output under 70kW
  • The gas system has a gas volume less than 0.035m3 
  • The pipework is less than or equal to 35mm

You will not need Commercial Gas Safe Registration if you work within these parameters. For boilers with a total output over 70kW, you will need to undertake additional training. 

To get the most out of the move to light commercial installation work, we recommend engineers of all experience levels are trained on the boilers they install. After all, products are always evolving and it’s always a good idea to brush up on best practises. 

Here at Ideal Commercial, we offer free training courses for installers at various locations across the country, including courses on models that are suitable for light commercial applications. 

Top Considerations When Undertaking Light Commercial Boiler Installations

The three main things to consider when undertaking light commercial boiler installations are specification, space and selection. 


Light commercial installations can cover a host of sites, ranging from small business units such as hairdressers and shops to large family homes, depending on their output requirement. Heating and hot water use tends to vary considerably in these types of buildings, so it’s worth doing some research into the different light commercial products on offer and assessing which product will be most efficient and effective. 

Ensuring the boilers’ outputs match system requirements is key to allowing the boilers to run at their optimum efficiency level. You may find that boilers have been over or under specified, resulting in a boiler that is either overworked or inefficient.


Space considerations are also key. In many light commercial applications space is at a premium compared to larger projects. It’s important to consider boiler ranges that are suitable for smaller spaces. Ideal Commercial’s Evomax 2, for example, is smaller than most and therefore a popular choice with our customers working on light commercial projects.

You should also consider any other equipment that may be necessary. Commercial boilers do not have an expansion vessel built into them, so you may need to allow space to include an expansion vessel(s) as part of the overall system.  Additionally, if you need to use more than one boiler, a frame and header kit could be used to mount the boilers, giving a reduced installation time.


So you’ve specified the heating and hot water demand and measured up your space - now it’s time to find the right product for your project. 

While some installers who are more comfortable with domestic boilers may look to use multiple domestic boilers in a light commercial setting to achieve the required power output, this is not the best solution. It may be perceived as a slightly cheaper option on unit price, but you’ll be stacking up problems for the future as cascading domestic boilers may reduce their lifespan. 

What may be less expensive initially could end up costing your customer more in repairs and early replacements, which in turn could prove costly to your reputation.

The best way forward is to conduct thorough research to help you select the right light commercial boiler for your project. Learning about the different boilers available to you and how to install them is key to making the most of light commercial opportunities. 

Start Your Light Commercial Training Now

The key to making a successful move from domestic to commercial installation is to do plenty of research. Understand what different products are out there and familiarise yourself with warranties and after-sales support, as these can differ from domestic boilers. 

Once you have decided on your boiler choice, have a look at the training available for that product. Ideal Commercial training courses are available to help familiarise you with our range of boilers. From understanding plant room surveying to advice on installing, servicing and repairing our condensing boilers, you’re sure to find a commercial training course to suit your needs. 

Book your course today and get started on your exciting transition to becoming a light commercial boiler engineer. 

Variations of this article first appeared in BSEE magazine, August 2017 and PHAM News, October 2018

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