How does my boiler work?

Boilers are a key part of any central heating system, helping to keep your entire home warm all year round. To say they’re important would be a bit of an understatement. But even so, not many people understand how exactly their boiler works. Fortunately, we’re here to help.

The basics

In a nutshell, your boiler works by burning gas, or gasses, inside a pressure vessel, which heats the water that pumps around your home and into your radiators. When the hot water reaches the radiators they emit the heat into your rooms.

In a nutshell, your boiler works by burning gas, or gasses, inside a pressure vessel, which heats the water that pumps around your home and into your radiators.

The details

The gas is supplied into your home through pipes from the mains, generally straight into the combustion chamber of your boiler. Here the gas is split into small streams, each one going over a small electric ignition – which will set them alight.

Once they’ve been lit, the series of small flames warm up what’s known as the heat exchanger. A heat exchanger is a twisty copper pipe that bends back and forth as many times as possible.

Water runs through these twists and turns, exposing it to the heat for the maximum amount of time feasible – and subsequently will get as hot as is achievable in that time.

The heat exchanger is a twisting copper pipe which allows the water the greatest opportunity to absorb heat

The heated water is then circulated around your home via your pipes. It goes into your radiators where the warmth can be emitted – or radiated out - and then once the water cools down it returns to the boiler to be reheated – and the cycle continues. A big loop of heating up and cooling down.

Being boiler safe

As you can imagine, because of the combustible gasses involved with this process, boilers can be potentially dangerous if amateurs work them on.

It’s important that any tradesperson you hire is on the Gas Safe Register. At Local Heroes, we personally vet all the heating engineers listed on our site, including for Gas Safe registration.