gas boiler being installed

A Guide to how your Boiler Works

Quietly ticking away in an air cupboard or up in your attic space, it’s pretty easy to forget about your home’s boiler. However, when you really stop to think about what a quality heating system offers, it can be genuinely eye-opening.

A hundred years ago, the average person would have given an arm and a leg for a way to conveniently heat their homes, however, things have most definitely changed for the better. Here in the UK, we’re pretty reliant on our boiler systems. With over 26 million units in homes up and down the country, they are easily one of the most efficient ways to ensure that our homes are cosy and our showers remain hot.

However, for all the good they do for your home, do you really know how your boiler works? These marvels of technical ingenuity are part of a larger system that helps to keep you comfortable but, for many homeowners, how your boiler does this remains a bit of mystery. As heating experts who have worked with countless boilers over the years, we at West London Gas know a thing or two about how your boiler works and how to keep it running as it should.

Because of this, we think it’s important for everyone to learn a little more about how their boiler ticks over, especially when it comes to keeping an eye on any problems that could arise. With this in mind, here is our handy guide on how your boiler system heats your home.

Basic principles at work in a boiler

In layman’s terms, a boiler works by transferring heat into water which is then transported throughout your home. Known as ‘wet heating’ this is the most common option for UK homes and is also one of the most efficient ways of supplying your home with enough heat on a consistent basis.

As soon as you want to warm your house or use hot water, a simple flick of a switch will set off the ignition and get to work. With a continuous supply of gas from the national gas grid into the unit, the boiler ignites a fire, heating up a component known as a heat exchanger which is connected to a pipe carrying cold water. The heat exchanger does exactly what the name entails, transferring energy from the ignition to the water which then heats it up to temperature.

This warm water is then circulated throughout your home, heating up radiators, ensuring hot water comes out of your taps and that your showers aren’t unbearably cold. This water is then transported back to the boiler where it was first stored to be used again when needed. This means that the water that is used throughout your home is permanently sealed into your system, unless maintenance work is carried out.

Components of a heating system

While your boiler is the metaphorical beating heart of the heating system, there are a variety of pieces that form a full circular network. For starters, a heating system relies on a fuel source to operate. While in our previous example we mentioned natural gas, there are a range of fuel options to best fit the homeowner, from liquid petroleum gas and biomass to electricity.

The pipework that runs throughout your system is also a huge part of your home’s central heating system, pumping hot and cold water around your home. These pipes are usually made of copper or plastic and can come in a range of sizes from 8mm to 35mm in diameter. The pipes are connected to a pump which is the component that pushes the water around the system and a motorised valve which is responsible for ensuring the water reaches the correct point of the house.

There are also a host of components that allow for increased control over your heating system. For example, you have your boiler thermostat, which controls the temperature of the water, a programmer which can allow you to decide when you want the system to be on or off and thermostatic radiator valves (TRVs) which regulate the flow of water into radiators.

Deciding in the right boiler system for you

While many boilers work in much the same way, there are a variety of models to choose from with each offering a host of pros and cons. Knowing the three main types of boilers that are most commonly used can help you to both figure out what unit you own and to ascertain whether you need an upgrade.


By far the most popular of the boiler types, ‘combi’ is a shortened term for a combination boiler. Combining a high-efficiency water heater and boiler into a single compact unit, combis are by far the smallest option on the market, making them perfect for smaller properties.

These units operate by using water directly from the mains, meaning that your water is heated much quicker. This has the added benefit of making combis some of the most efficient models on the market. However, they can sometimes lack enough pressure in larger houses, which is something you should consider.


Rather than having your boiler in one unit, system models will require a cylinder to store hot water. While this means that the whole system takes up more space, having a dedicated water cylinder does have its benefits.

For example, system boilers are much better at providing homes with superior water pressure, making it suitable for larger properties with more than one bathroom. It can also be useful for homes that lack the attic space for a conventional system.


The largest of the three most common systems, a conventional unit is made up of a boiler, heating cylinder and cold water storage tanks which are situated in the attic space of the property. These are usually found in houses that are fitted with older radiators that wouldn’t be able to handle the higher water pressure that a combi or system boiler creates.

The right boiler for you will be down to how your home operates, however, if you’re unsure what works best for you, getting in touch with an industry professional can be a great way to feel confident in your purchase.

The importance of regular services

As you can see, there are a host of components that go into a working boiler, which is why it’s so important to keep on top of your servicing requirements. Aside from the fact that by keeping up with annual servicing will ensure your system remains working and in warranty, there is also a range of benefits you can expect to gain.

For starters, by having a boiler service, you can maximise your system’s efficiency, meaning that you could potentially save a significant amount of money in annual bills.

It’s also important for safety reasons to have your boiler regularly checked by a professional. As your system uses volatile substances like gas or LPG, a broken boiler can pose a significant risk to the household. Carbon monoxide leaks are also a genuine issue posed by faulty heating systems, which is why it’s so important to ensure that your unit is checked over by a licenced professional.

Looking for a quality heating engineer you can trust? Get in touch with West London Gas today

Your boiler system is an essential part to your home, which is why it’s so important that you keep it in top condition. They are also complex pieces of equipment that require the expertise of a qualified heating engineer. If you’re looking for a technician in the West London area, our team is ready and waiting to hear from you.

Offering a range of high-quality heating services, from boiler installations and servicing to breakdown cover and intelligent heating controls, we can ensure that your home is running at optimum efficiency. If you would like to learn more about how we can help you with your heating requirements, visit our website or get in touch with a member of our team today on 02084 343 644.

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