Vaillant vs Viessmann:Which is more popular?
In September 2026, Vaillant had more branded searches than Viessmann among boiler brands in the United Kingdom. Vaillant had about 9,900 branded searches, while Viessmann had 3,600. Vaillant made up 22.1% of all boiler brand searches we track, and Viessmann accounted for 8%. When we asked ChatGPT and Google AI Overviews about boiler brands, Vaillant appeared in all four answers and Viessmann in three. Vaillant was mentioned before Viessmann in every answer.
Who do people search for more?
Vaillant, about 3 searches for every 1 for Viessmann
Who does AI mention more?
Vaillant, mentioned in every answer we collected
Who does AI recommend more?
Vaillant, named ahead of Viessmann in every answer
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Top boiler brands in ChatGPT and Google AI Overviews
In three ChatGPT questions and one Google AI Overview, Vaillant appeared in all four answers. Viessmann was mentioned in three out of four: in all three ChatGPT answers, but not in the Google AI Overview. Vaillant was listed before Viessmann in every answer.
Most recommended by AI
Brands get a higher ranking if they are mentioned earlier in the answers.
Worcester Bosch1st- Vaillant2nd
Viessmann3rd
Ideal4th
Baxi5th
Mentioned by AI
Each dot is one answer, filled in when that answer mentions the brand.
- Worcester Bosch4 of 4Named in 3 of 3 ChatGPT answersNamed in 1 of 1 Google answers
- Vaillant4 of 4Named in 3 of 3 ChatGPT answersNamed in 1 of 1 Google answers
- Ideal3 of 4Named in 3 of 3 ChatGPT answersNamed in 0 of 1 Google answers
- Viessmann3 of 4Named in 3 of 3 ChatGPT answersNamed in 0 of 1 Google answers
- Baxi1 of 4Named in 1 of 3 ChatGPT answersNamed in 0 of 1 Google answers
See every answer about boiler brands
4 answers
Asked ChatGPT
“Which boiler brand should I get in the UK?”
Asked ChatGPT
“What are the best boiler brands in the UK?”
Asked ChatGPT
“What's the most reliable combi boiler brand in the UK?”
Searched Google, AI Overview
“combi boiler”
Google showed no AI Overview for this search.
Searched Google, AI Overview
“new boiler”
Brands are shown in the order each answer named them. The survey took place in United Kingdom on October 22, 2026.
Is Vaillant or Viessmann more popular in search?
This chart shows how often people search Google for Vaillant and Viessmann by name. Each line represents a brand's share of searches for all five boiler brands we track, month by month, from searches in United Kingdom.
Share of searches by month for Vaillant, Viessmann. The figures are in the table below the chart.
View monthly share of searches table
| Month | Worcester Bosch | Ideal | Vaillant | Baxi | Viessmann |
|---|---|---|---|---|---|
| Oct 2025 | 30.5% | 30.5% | 20.4% | 11.1% | 7.4% |
| Nov 2025 | 31.2% | 31.2% | 20.8% | 9.3% | 7.6% |
| Dec 2025 | 32.4% | 32.4% | 17.7% | 9.7% | 7.9% |
| Jan 2026 | 29.2% | 35.6% | 19.4% | 8.7% | 7.1% |
| Feb 2026 | 32.4% | 32.4% | 17.7% | 9.7% | 7.9% |
| Mar 2026 | 32.4% | 32.4% | 17.7% | 9.7% | 7.9% |
| Apr 2026 | 34.4% | 28.1% | 18.8% | 10.2% | 8.4% |
| May 2026 | 31.8% | 26% | 21.3% | 11.5% | 9.4% |
| Jun 2026 | 36.3% | 24.3% | 19.9% | 10.8% | 8.8% |
| Jul 2026 | 36% | 24.1% | 19.6% | 13.1% | 7.1% |
| Aug 2026 | 33.1% | 27% | 22.1% | 9.8% | 7.9% |
| Sep 2026 | 33% | 27% | 22.1% | 9.8% | 8% |
How has the Vaillant and Viessmann comparison changed over the last 12 months?
3 findings
- Vaillant was ahead of Viessmann in every measured month of the 12 months ending September 2026.
- Across the 12 months ending September 2026, Vaillant’s share of searches among boiler brands in the United Kingdom moved from 20.4% to 22.1%, and its estimated monthly branded searches moved from 14.8K to 9.9K.
- Across the 12 months ending September 2026, Viessmann’s share of searches among boiler brands in the United Kingdom moved from 7.4% to 8%, and its estimated monthly branded searches moved from 5.4K to 3.6K.
How did search popularity change for United Kingdom boiler brands in September 2026?
2 changes
How are branded searches counted?
2 search terms
Brandwave collects information about searches that people make online using Vaillant’s and Viessmann’s names. When viewed over time, estimated search volumes for these branded terms can be used to understand whether interest in the brands is growing, holding steady, or fading.
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