In 2021, Baelz was celebrating its 125th anniversary! Bit by bit we would like to collect pieces of this long history on our website: Great milestones and little anecdotes, findings from the Baelz archive, plenty of technology, but also some personal stories.

Share with us! Send a message to marketing@baelz.de, telling us what you associate with Baelz: your experiences, a historical photo or whatever else you would like to recount. We look forward to your contributions.

The principles that have always characterized Baelz will continue to exist in the future: Innovative. Sustainable. Congenial!



Founder Wilhelm Bälz. Like his father, Wilhelm Baelz (1863 - 1945) also became a master coppersmith. He soon recognized that the emerging industry had a need for heating technology solutions. Originally from Bietigheim, he founded W. Baelz & Cie in Düren near Cologne. He planned and built steam and condensate plants and - even in those early days - developed processes for waste steam utilization. From Düren, Wilhelm Baelz supplied the entire German industry.


Innovative. Sustainable.

Back home in Heilbronn. Already an thriving municipality, Heilbronn offered the steam specialist Wilhelm Baelz the opportunity to develop former pasture land on the River Neckar. A new industrial area was born – Baelz bought a plot of land in Koepffstrasse 5 and founded W. Baelz & Sohn GmbH & Co – here a photo dating back to 1923. In addition to trade and plant planning and construction, he also ran a "consulting center for heat utilization", so even back then he was committed to sustainability.



Invoice by postcard. Wilhelm Baelz worked together with many of the companies in the Heilbronn industrial area. Billing was done by postcard, on which there was even space for an sticker: "Do you have defective manometers?", advertising for "Schäffer & Budenberg, Magdeburg". With good reason: son Helmut Baelz (1910 - 1994) was undergoing technical training there. By the way, a branch of this company is the Baelz partner in the Netherlands to this day.



The founder’s son Helmut Baelz. Just 30 years old, Helmut Baelz, the youngest son of Wilhelm Baelz, wrote an order confirmation on his 'hermes baby' on 12 July 1940 to the company L. Brüggemann KG, Alkoholfabrik, also still located in the Heilbronn industrial area today. Helmut Baelz joined the company in the 1930s after years of training outside the company and learned both business and technical skills from his father.


Innovative. Sustainable. Congenial.

Out of the rubble and a certificate. The terrible Second World War also had a deep impact on the Baelz company: During the devastating air raid on Heilbronn on December 4, 1944, the company buildings of W. Baelz & Sohn were completely destroyed. Shortly before the end of the war, Helmut Baelz was drafted and fell into American captivity. On December 24, 1945, shortly before his release from captivity, he received a certificate as "recognition for special achievement in heating construction" – he had successfully advised the American armed forces on heating their accommodation.


Innovative. Sustainable.

The first in-house product. Helmut Baelz recognized the need of post-war industry for automation and consistent product quality and developed the rod expansion thermostat. But he wanted to stay close to the customer, offer solutions and not produce them himself. Christian Bürkert, Ingelfingen, became his new production partner. Helmut Baelz thus laid the foundation for what is now called the 'extended workbench'.


Innovative. Sustainable.

Heating on demand. Either too hot or too cold: heating technology in the 1950s worked on the principle of "all or nothing". Unable to accept this wastefulness, Helmut Baelz invented the world's first outdoor temperature-dependent heating controller, Wetterpilot, and soon  made it available with night setback. Many other new developments in control technology followed, also for industrial controllers. Here, too, a long-standing partnership in production was established: the Hoerner company in Eberstadt built the devices, which were used throughout Europe.


Innovative. Sustainable.

District heating for swimming pool water: One of the first of today's thousands of systems: Baelz heat exchangers with control according to Baelz-thermodynamic® are installed in the newly built Südbad Dortmund. Installations designed for durability and materials of the highest quality ensure decades of plant life without breakdowns or need for replacement.


Innovative. Sustainable.

Promoting young talent. In 1978, Helmut Baelz set up the Baelz Foundation for the field of Control Engineering at the Technical University of Applied Sciences of Berlin in the degree course for Supply and Energy Technology. In the meantime, other technical universities have been integrated into the work of the Baelz foundation, creating a stable network of all technical universities teaching supply technology in Germany. Today Prof. Dr. Uwe Baelz continues the work of his father in the Baelz foundation.


Innovative. Sustainable.

Off into space! Baelz never ventured into space travel, but chose this design to further publicize the technology of the controlled ejector developed in the early 1970s: Preserving flow energy, economizing on materials, saving energy. Still relevant to this day!