Theodor Stiebel founded a small factory for immersion heaters in Berlin in 1924 - he was driven to develop products with low energy consumption. Today, the company has over 3700 employees and generates sales of more than 500 million euros. And energy efficiency is its brand essence.

The year was 1923, when the engineer from Braunschweig was looking for an alternative to the error-prone piston immersion boilers. His solution is a handy device with a ring-shaped hollow cylinder and a wall thickness of three millimeters. The advantage is that this small immersion heater heats up quickly and cools down again quickly, thus saving energy.

Theodor calls the device a ring immersion heater and asks his uncle Carl if he could produce some models for him. Carl Reese owns a metalworking company in Lower Saxony. Of course he wants to help his 27-year-old nephew. He also recognizes that the device is simply good. So good, in fact, that they presented it together at the Leipzig Spring Fair in 1924 and received the first 100 orders, which Carl immediately filled. The proud selling price per immersion heater was three Reichsmarks, which today is equivalent to just under twelve euros.

That same spring, Theodor Stiebel founded his own company, "ELTRON Dr. Theodor Stiebel" in the backyard of Reichenberger Strasse 143 in Berlin-Kreuzberg. The simple logo with the name between two red bars is designed by his cousin Paul Reese. The start-up capital of 20000 Reichsmark came from his two uncles, Carl Reese and the Hamburg hotelier Hermann Stiebel. Within the family, people help each other.

Theodor hired ten employees. From 1925, he produces the ring immersion heaters himself. Within a year, production jumped to 60,000 units. Stiebel rents further premises. In 1927, he already had 26 employees and achieved an annual turnover of 184745 Reichsmark. He exports the first immersion heaters to Australia, India, China and South America, and establishes branches in London and Zurich.

Theodor now considers how to heat more water in a better way. In early 1928, he introduces his first small instantaneous water heater with 1000 watts. Hot water whenever it is needed - that is revolutionary. Right off the bat, annual production is 35500 units. The businessman and inventor Stiebel is satisfied: He wants to further develop the two-stage technology with which the water is heated.

Theodor marries his partner Gustel in 1930, but he works virtually around the clock: In 1931, he launches a storage tank with a capacity of three liters, and over the next few years adds overflow, high-pressure and boiling water storage tanks with capacities of up to 600 liters.

By 1932, he already had 150 employees and annual sales of one million Reichsmarks. His motto: Our products must be energy-efficient. In 1938, he had registered 35 German and twelve international patents and at the end of the year had 208,000 immersion heaters, 40,50 bath storage heaters and 620 water boilers on his books. In 1939, 350 employees generate annual sales of 3.2 million Reichsmarks. During the Second World War, the Berlin plant was destroyed, Stiebel moved production to Holzminden in Lower Saxony and did not manufacture hot water appliances again until 1946. By then he was already divorced. In 1947, he married for the second time. With Margret he has three children, daughter Angelika and sons Frank and Ulrich. Business was also good for the entrepreneur: The Stiebel-Eltron instantaneous water heater became synonymous with a modern bathroom. In 1950, Theodor Stiebel decides on a more modern company name, from now on operating under Stiebel Eltron.

To the outside world, everything seems fine, but nevertheless Theodor Stiebel takes his own life at the age of 66. In 1960, his sons Frank and Ulrich each inherit half of the company with their father's 160 patents. In 1976, the company begins to develop devices for the use of renewable energy. In 2013, Ulrich Stiebel establishes the Stiebel Family Foundation and transfers his share to it. Today, the operational business of the GmbH is managed by two managing directors. In 2017, the company breaks through the 500 million euro mark and now also produces night storage heaters, heat pumps and solar systems. Theodor Stiebel would have liked his company to consistently follow his philosophy: to produce environmentally friendly and efficient technology. ®

Author: Jennifer Bligh