Boiler brands rated Vaillant


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

Vaillant boilers

Vaillant offers four 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. The EcoTec Plus range comes in three power levels – the more hot water taps you have the higher power you will need. 

The EcoTec Plus 937 combi storage boiler can store 15 litres of hot water to reduce the time it takes to deliver piping hot water to your taps. The top-of-the range EcoTec Exclusive is suitable for larger properties and has a three-year warranty.

Vaillant also offers an EcoTec Plus open-vent boiler – the type for homes that have the traditional plumbing arrangement of a cold water supply tank and hot water storage cylinder. This is available in four heat outputs to cater for small, medium and larger homes.

The EcoTec Plus system boiler provides an even wider range of outputs (12-37kW) for homes that use a hot water cylinder but have a system boiler.

To find out more details on the features, pros and cons of each of these Vaillant boilers visit the Which? boiler reviews.

Vaillant boiler prices

Vaillant boilers cost between £740 and £1500 depending on the type and size of boiler you need for your home. 

Vaillant boilers – The Which? verdict

Vaillant is the second most popular gas boiler brand with Which? members.

Which? members can log in to unlock and view full scores for Vaillant boilers in the table below. If you're not already a member, sign up to try out full access for one month, for just £1.

Brand data for Vaillant gas condensing boilers
Which? Survey resultsScore
Brand reliabilitySubscriber only content
Which? Customer ScoreSubscriber only content
Ownership among Which? members with gas boilersSubscriber only content
Most common faults experienced by owners
Water leaking from the boilerSubscriber only content
Boiler noisy in operationSubscriber only content
Boiler keeps switching itself offSubscriber only content
Control panel displays and error code and cannot be resetSubscriber only content
Problem with built-in controlsSubscriber only content
Boiler completely broke downSubscriber only content
Water leaking from condensate pipeSubscriber only content

Table notes

Average customer score is 80% and average reliability score is 75%, based on responses from 4,354 Which? connect panel members. Scores are based on boilers bought since April 2005. Brand reliability sample size (848). Customer score sample size (847).

Vaillant warranty and servicing

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 and 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 general enquiries

01634 292 300 

Vaillant technical enquiries

0906 802 0251

For top tips on choosing a new boiler see our guide how to buy the best boiler.

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