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16 November 2020

Vaillant boilers rated

We take a close look at how reliable Vaillant boilers are, courtesy of our boiler owners' survey
Matthew Knight

German brand Vaillant has been in the heating market for more than 135 years. Vaillant now sells products in more than 80 countries, including the UK.

Vaillant offers six types of combi boilers that supply heat and instant hot water. The range starts with the basic EcoTec Pro, which is suitable for smaller homes. Vaillant also produces EcoTec Plus, EcoTec Exclusive, EcoFit Sustain and Ecofit Pure combi boilers. You can find more details about the individual products in these ranges in our Vaillant boiler reviews.

More than 7,000 members of the general public take part in our annual boiler brand reliability and customer satisfaction survey, enabling us guide you to the best and worst boiler brands. We also conduct a survey with more than 153 trusted boiler engineers to get their independent views on which boiler brands are the best.

Which? verdict on Vaillant boilers

Below, we've collated all of our survey results for Vaillant boilers. We reveal how reliable Vaillant boilers are, what Vaillant boiler owners think of their boiler, what trusted engineers think of Vaillant boilers' build quality, and much more.

The reliability and customer score are based on responses from a May and June 2020 survey of 7,500 boiler owners.Engineer recommendation, build quality, availability of parts and spares, and ease of fixing a common fault and ease of servicing are based on responses to a June 2020 survey of 153 Which? Trusted Traders heating engineers.

Which? members can log in to see what owners and engineers make of Vaillant boilers. If you're not already a member, try Which? to unlock the scores in our table below.

Overall score
Member content
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Customer score
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Engineer recommendation
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Build quality
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Availability of parts and spares
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Ease of fixing a common fault
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Ease of servicing
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How much do Vaillant boilers cost?

Vaillant boilers cost between £740 and £1,500, depending on their type and size.

Choosing the best Vaillant boiler

Vaillant boilers are typically supplied with a two-year parts and labour warranty. You must get the boiler serviced after the first 12 months to qualify for the second year of warranty. The guarantee card should be registered within 30 days of the boiler being installed.

Vaillant claims to have a team of 200 Gas Safe-registered engineers trained to repair and service Vaillant boilers.

Vaillant service enquiries

01773 596 660

Vaillant repairs and spares

Vaillant's own team of engineers carry spare parts with them.

Vaillant also offers two options for boiler breakdown cover which include an annual service.

Vaillant breakdown cover

0800 032 4597

Vaillant contact details

You can contact Vaillant by letter at:

Vaillant Ltd.

Vaillant House, Trident Close,

Medway City Estate


Kent ME2 4EZ

or through its website (vaillant.co.uk).

Vaillant general enquiries

01634 292 300 

Vaillant technical enquiries

0906 802 0251

For advice on choosing a new boiler, see our expert guide on how to buy the best boiler.

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