Combi boilers are extremely economical, making them the best-selling boiler in the country.

Combi boiler system
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Combi boilers work by heating water directly from the mains.

This means that you can get hot water whenever you like without having to turn your boiler on in advance.

A big advantage to combi boilers is that they’re very economical. This is because they don’t waste energy heating water that doesn’t get used.

Combi boilers are also popular because they’re small and compact. You can easily hang them on walls and fit them in cupboards.

Is the combi boiler right for me?

Combi boilers are great for relatively small homes as they take up very little space and are best at supplying one hot water outlet at a time. If you have a home with multiple bathrooms, a combi boiler would probably struggle to supply both with hot water simultaneously.

Combi boilers require sufficient water pressure to perform well. If you’re not sure how good your water pressure is, it’s a good idea to get some professional advice before you get a combi boiler.

Types of combination boilers

Combi instant
Combi instantaneous boiler

This is the most common boiler type in the UK and supplies hot water directly to taps and other outlets.

Combi instant condensing
Combi instantaneous condensing boiler

This is similar to the combi instantaneous boiler but is usually more efficient.

Combi storage
Combi storage boiler

This combi boiler type has an internal storage system to store a limited amount of hot water.

Combi storage condensing
Combi storage condensing boiler

This is similar to a combi storage boiler but is usually more efficient.

Combined Primary Storage
Combined Primary Storage Unit (CPSU)

This is a boiler that can hold a large amount of water, so it can provide a high water flow on demand.