Vaillant boiler guide

Vaillant boiler guide

by Matthew Knight

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

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 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. You can find more details about the individual products in these ranges in our boiler reviews.

Thousands of Which? members take part in our annual survey of boiler brand reliability and customer satisfaction, which enables us to guide you to the best and worst boiler brands. We also conduct a survey with more than 100 trusted boiler engineers to get their independent views on which boiler brands are the best.

Boiler brand guide
Brand data for Vaillant boilers
Overall scoreM
Customer score
Engineer recommendation
Build quality
Availability of parts and spares
Ease of fixing a common fault
Table notes
1 The reliability and customer score are based on responses from a survey of 10,779 members of Which? Connect about their boilers that took place in May 2015. Reliability sample size (808). Customer score sample size (821).
2 Engineer recommendation, build quality, availability of parts and spares and ease of fixing a common fault are based on responses to a survey of 110 Which? Trusted Trader heating engineers that took place in March 2015.


Member Content

How much do Vaillant boilers cost?

Potterton 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 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.