Plumbers in Frankfurt that AI assistants recommend
We asked ChatGPT, Claude and Gemini the four questions a buyer asks when looking for plumbers in Frankfurt, three times each, in German, and counted who they named. These are the businesses named in two or more of the 36 answers.
Names are printed as the assistants wrote them. We have not checked that any of them is good, open, or real.
- Answers
- 36
- Businesses named
- 80
- Named only once
- 68
- Named by 2+ assistants
- 4 of 12
- Named again on a rerun
- 3%
Edition September 2026. Download the data
Asked for plumbers in Frankfurt, ChatGPT, Claude and Gemini most often named Schäfer Haustechnik (17% of answers), Barth Haustechnik (8%) and Hermann & Sohn GmbH (8%). Across 36 answers they named 80 different businesses, 68 of them only once. Each of four buyer questions was asked three times, in German, in September 2026.
The ranking
The AI Recommendation Rate is the fraction of the 36 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 | AI Recommendation Rate | ChatGPT | Claude | Gemini | Questions | Avg. position |
|---|---|---|---|---|---|---|---|
| 1 | Schäfer HaustechnikAlso written Schäfer Haustechnik GmbH, Schäfer Sanitär- und HeizungstechnikIs this your business? | 95%: 8 to 32% | 0% | 0% | 50% | 4 of 4 | 2.5 |
| 2 | Barth HaustechnikAlso written Barth Sanitär- und Heizungstechnik GmbH, Barth Haustechnik GmbHIs this your business? | 95%: 3 to 22% | 0% | 0% | 25% | 3 of 4 | 1.7 |
| 3 | Hermann & Sohn GmbHIs this your business? | 95%: 3 to 22% | 0% | 0% | 25% | 3 of 4 | 2.3 |
| 4 | Klaus MüllerAlso written Klaus Müller Heizungsbau GmbH, Klaus Müller Sanitär- und Heizungstechnik, Klaus Müller Sanitär-Heizung-KlimaIs this your business? | 95%: 3 to 22% | 0% | 0% | 25% | 3 of 4 | 4 |
| 5 | A. K. MüllerAlso written A. K. Müller GmbH Sanitär-Heizung-Klima Frankfurt am Main, A. K. Müller Sanitär- und Heizungstechnik GmbHIs this your business? | 95%: 2 to 18% | 0% | 17% | 0% | 2 of 4 | 1 |
| 6 | Köhler Heizungs- und SanitärtechnikAlso written Köhler Heizungs- und Sanitärtechnik GmbH, Köhler Heizungs- und Sanitärtechnik GmbH, Frankfurt am MainIs this your business? | 95%: 2 to 18% | 8% | 8% | 0% | 1 of 4 | 1.5 |
| 7 | Böhm & Sohn GmbHIs this your business? | 95%: 2 to 18% | 0% | 0% | 17% | 1 of 4 | 2 |
| 8 | H. Schramm GmbHIs this your business? | 95%: 2 to 18% | 8% | 8% | 0% | 1 of 4 | 2.5 |
| 9 | Peter MüllerAlso written Fa. Peter Müller Sanitär- und Heizungstechnik, Peter Müller GmbH – Sanitär Heizung KlimaIs this your business? | 95%: 2 to 18% | 0% | 8% | 8% | 2 of 4 | 2.5 |
| 10 | Böhm Sanitär- und HeizungstechnikAlso written Böhm Sanitär-Heizung-Klima GmbHIs this your business? | 95%: 2 to 18% | 0% | 0% | 17% | 2 of 4 | 3 |
| 11 | Günther Energie- und GebäudetechnikAlso written Günther Energie- und Gebäudetechnik GmbH, Günther Sanitär- und Heizungstechnik GmbHIs this your business? | 95%: 2 to 18% | 8% | 8% | 0% | 2 of 4 | 3 |
| 12 | Müller & SöhneAlso written Müller & Söhne Haustechnik, Müller & Söhne Sanitär-Heizung GmbHIs this your business? | 95%: 2 to 18% | 0% | 0% | 17% | 2 of 4 | 4 |
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. 68 more names came up in a single answer and are counted above but not listed.
Is this your business?
See what the assistants say about your business today. The free checker asks ChatGPT, Claude, Gemini and Grok two of the Index questions for this category, with the category and the place already filled in, and shows every answer word for word. About 30 seconds, no sign-up.
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 | Gemini |
|---|---|---|---|
| 1 | Köhler Heizungs- und Sanitärtechnik8% | A. K. Müller17% | Schäfer Haustechnik50% |
| 2 | H. Schramm GmbH8% | Köhler Heizungs- und Sanitärtechnik8% | Barth Haustechnik25% |
| 3 | Günther Energie- und Gebäudetechnik8% | H. Schramm GmbH8% | Hermann & Sohn GmbH25% |
| 4 | No other name twice | Peter Müller8% | Klaus Müller25% |
| 5 | Günther Energie- und Gebäudetechnik8% | Böhm & Sohn GmbH17% |
ChatGPT named no business in 4 of its 12 answers. Claude named no business in 3 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/frankfurt"><img src="https://aigrow.gg/badges/index/2026-09/plumbers/frankfurt.svg" width="312" height="100" alt="Named by AI assistants: Plumbers in Frankfurt, AIGROW AI Visibility Index, September 2026"></a>The questions
Asked word for word, three times each, to every assistant, 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 Frankfurt?Who is the best plumber in Frankfurt?
- 2Bei mir zu Hause in Frankfurt leckt ein Rohr. Welchen Sanitärbetrieb soll ich anrufen?I have a leaking pipe at home in Frankfurt. Which plumbing company should I call?
- 3Ich brauche heute Abend einen Notdienst-Installateur in Frankfurt. Wen empfiehlst du?I need an emergency plumber in Frankfurt tonight. Who would you recommend?
- 4Welchem Installateur in Frankfurt würdest du den Austausch eines Warmwasserspeichers anvertrauen?Which plumber in Frankfurt 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
- 36 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.
Where the assistants look
The sites read most often, with web search on, before the assistants answer about this category in Germany. From the AI Source Map: 8 answers.
- trustlocal.de
- Read in 88% of the answers
- reddit.com
- Read in 88% of the answers
- werkenntdenbesten.de
- Read in 75% of the answers
Elsewhere in the Index
- Also in Frankfurt
- DentistsLawyersAccountantsGymsReal estate agenciesRestaurants
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 · published by Guglielmo Paesano, founder of AIGROW · data under CC BY 4.0