Our pick of the best combi boilers 2020

Originally published 27 January 2020. Models and ranges have since changed - see our latest guides.

Combi boilers are not the sort of thing you think about all the time, usually only when they need servicing, repairing or replacing. There are all sorts on the market and the top models change all the time, so it can be hard to know which to choose.

How combi boilers work

A combi boiler is a water heater and a central heating boiler in one. It heats water directly from the mains when you turn on a tap, so there is no need for a hot water storage cylinder or a cold water tank in the roof.

The benefits of combi boilers

• Cost effective to run compared to other boiler types
• More energy efficient as water is heated instantly rather than stored
• Space-saving with no cylinder or feed tank
• Hot water at mains pressure, so a powerful shower without a separate pump

1. Vaillant ecoTEC Exclusive

Outputs at the higher end of the scale, 35kW and 43kW, make this ideal for larger homes, producing up to 17 litres of hot water per minute. It has an excellent efficiency rating, high quality parts and a built-in heat recovery system.

2. Vaillant ecoTEC Plus

Outputs from 25kW make the ecoTEC Plus ideal for small to medium homes. It is energy efficient, high quality and has a Quiet Mark award for being so quiet. It delivers hot water within five seconds.

3. Greenstar 30i

Worcester Bosch’s bestseller and a Which? Best Buy. A low energy pump reduces electrical usage, outputs range from 8.2kW to 24kW, and it fills a standard kitchen sink in 45 seconds.

4. Viessmann Vitodens 200-W

Suitable for houses of all sizes and hugely efficient, with up to 98% of fuel converted to heat and an A energy efficiency rating. It has a MatriX cylinder burner, touchscreen colour controls and a quiet low speed fan.

5. Baxi EcoBlue Advance Combi

Available in 24, 28, 33 and 40kW outputs, easy to install with simple controls, reliable and A-rated. It has been endorsed by the Energy Saving Trust.

If you need a new combi boiler, our guide on combi and system boilers helps you choose, or get a fixed-price boiler installation quote.