Plumbers in Hamburg that AI assistants recommend
We asked ChatGPT and Claude the four questions a buyer asks when looking for plumbers in Hamburg, three times each, in German, and counted who they named. These are the businesses named in two or more of the 24 answers.
Names are printed as the assistants wrote them. We have not checked that any of them is good, open, or real.
- Answers
- 24
- Businesses named
- 53
- Named only once
- 46
- Named by 2+ assistants
- 4 of 7
- Named again on a rerun
- 5%
Edition September 2026. Download the data
Asked for plumbers in Hamburg, ChatGPT and Claude most often named Peter Jensen GmbH (29% of answers), H. C. Römer GmbH (17%) and Hansa Haustechnik GmbH (13%). Across 24 answers they named 53 different businesses, 46 of them only once. Each of four buyer questions was asked three times, in German, in September 2026.
The ranking
Share is the fraction of the 24 answers that named a business. The range under it is a 95% confidence interval: where two ranges overlap, the gap between those businesses could be chance.
| # | Business | Share | ChatGPT | Claude | Questions | Avg. position |
|---|---|---|---|---|---|---|
| 1 | Peter Jensen GmbH | 95%: 15 to 49% | 25% | 33% | 4 of 4 | 1.9 |
| 2 | H. C. Römer GmbH | 95%: 7 to 36% | 25% | 8% | 2 of 4 | 2.3 |
| 3 | Hansa Haustechnik GmbH | 95%: 4 to 31% | 8% | 17% | 2 of 4 | 2.3 |
| 4 | HSE-Haustechnik GmbH | 95%: 4 to 31% | 17% | 8% | 2 of 4 | 2.7 |
| 5 | Karl Krüger GmbH | 95%: 2 to 26% | 17% | 0% | 2 of 4 | 2 |
| 6 | W. Hartmann GmbH | 95%: 2 to 26% | 17% | 0% | 2 of 4 | 2.5 |
| 7 | Kurt Lemke GmbH | 95%: 2 to 26% | 17% | 0% | 2 of 4 | 3 |
Each assistant column is the share of that assistant's own answers. Questions counts how many of the four produced the name at least once; position is where it came in the answer's list, 1 being first. 46 more names came up in a single answer and are counted above but not listed.
What each assistant said
The same questions, the same number of times, and often different names. Each column is one assistant's top five from the ranking above, with the share of its own answers that named them.
| # | ChatGPT | Claude |
|---|---|---|
| 1 | Peter Jensen GmbH25% | Peter Jensen GmbH33% |
| 2 | H. C. Römer GmbH25% | Hansa Haustechnik GmbH17% |
| 3 | HSE-Haustechnik GmbH17% | H. C. Römer GmbH8% |
| 4 | Karl Krüger GmbH17% | HSE-Haustechnik GmbH8% |
| 5 | W. Hartmann GmbH17% | No other name twice |
Claude named no business in 1 of its 12 answers.
Named here? Put it on your site
Every business in the ranking was named in two or more answers. The badge says that and nothing more: no position, because the ranges above do not support one. It links back to this page, so anyone can check.
<a href="https://aigrow.gg/index/plumbers/hamburg"><img src="https://aigrow.gg/badges/index/2026-09/plumbers/hamburg.svg" width="312" height="100" alt="Named by AI assistants: Plumbers in Hamburg, AIGROW AI Visibility Index, September 2026"></a>The questions
Asked word for word, three times each, to every assistant through its API, in German. The English under each is our translation. The prompt is the one the free scan uses. No web search, no location and no chat history, so every answer starts from the same place.
- 1Wer ist der beste Klempner in Hamburg?Who is the best plumber in Hamburg?
- 2Bei mir zu Hause in Hamburg leckt ein Rohr. Welchen Sanitärbetrieb soll ich anrufen?I have a leaking pipe at home in Hamburg. Which plumbing company should I call?
- 3Ich brauche heute Abend einen Notdienst-Installateur in Hamburg. Wen empfiehlst du?I need an emergency plumber in Hamburg tonight. Who would you recommend?
- 4Welchem Installateur in Hamburg würdest du den Austausch eines Warmwasserspeichers anvertrauen?Which plumber in Hamburg would you trust to replace a water heater?
How to read this page
- What it measures
- Which names these models produce when asked cold, from what they learned in training. It is not a review, a rating or our recommendation, and a business missing here may simply be one the models were never shown.
- Why the ranges matter
- 24 answers is a sample. Asked again next month, most shares will move by a few points; the ranges say how far they could move by chance alone.
- One business, several spellings
- Branches, legal suffixes and spellings of one business are merged, and the other spellings are printed under its name. Names that might be two businesses are kept apart.
- A name is wrong
- If a business here is closed, misnamed or yours and you want it removed, tell us. We correct or remove it when the page is next published.
Is your business on this list?
The free scan asks the same assistants the questions your customers ask, scores whether they name you, and lists who they name instead.
Edition September 2026 · data under CC BY 4.0