Has your trusty old boiler packed in? We’ve all been there. With so many different types of boiler to choose from, starting the search for a new one can feel overwhelming.

It’s one of the biggest purchases you’ll ever make for your home, and something you’ll use almost every day – so naturally, you’ll want to get it right. 

You might be asking yourself: what’s the difference between condensing and non-condensing? Do I need a combi or conventional boiler if I need enough hot water for a big family? You might not even be sure if you have to replace the old boiler at all.

You’ve come to the right place. Here’s everything you need to know about the different ways of heating your home.

What are the different types of boiler?

Let’s start with the basics: what is a boiler? Most homes have one, but perhaps you’ve never given it much thought – until it stopped working! A boiler is a central heating unit that pumps hot water through the pipes around your home. It supplies the hot water to your taps, and heats up your radiators. Usually, it’s powered by your mains gas supply.

Here are the four most common types of boiler that you’ll come across when looking for a new one. 

1. Combi boilers

A combi or combination boiler is a single unit that provides both your hot water and your space heating. This means it takes up less space in the airing cupboard than other types of boiler, which can come with bulky hot water cylinders and cold water storage tanks.

The added benefit of a combi boiler is that, because they don’t need to refill or heat up the water before you can use it, they can give you instant hot water as soon as you turn on the shower or tap. They’re also more energy-efficient, quick to install, and more cost-effective.

The downside? Combis are not great at providing hot water to multiple bathrooms, so it won’t be the best choice for you if you’ve got a big household. 

For more, read our guide to combi boilers and installation costs.

2. System boilers

Most houses in the UK now have combi boilers, but you might prefer to buck the trend by choosing a system or conventional boiler. 

Unlike combis, system boilers use a separate hot water storage cylinder. This takes up more space, but it means they can supply a lot of hot water on demand. This makes them ideal for households where more than one person might want to take showers at the same time. 

System boilers take water directly from the mains, and while they’re a bit bigger than combi boilers, they don’t need a hefty feed and expansion tank. If you’re replacing an old system boiler, it’ll be a cheaper and easier installation process if you choose to get the same again, rather than change to a combi.

However, they’re a little extra work. The cylinder has to be kept insulated, and they won’t give you instant hot water like a combi can. 

3. Conventional boilers

Also known as regular boilers or heat-only boilers, conventional boilers are also suited to bigger households. They have a feed and expansion tank (usually kept up in the attic) and a hot water cylinder, which means they take up a lot of space.

If you’re getting a new boiler to replace an old conventional boiler, then you should consider sticking to the same type. It’ll be more cost-effective, because you may not have to replace the pipes in your house (as you would if you decided to switch to, for example, a combi).

Bear in mind, though, that like system boilers, they need to be kept insulated or they can lose heat very quickly.