Lollar plant 1 and 2


Location information, products and history: Lollar 1

Lollar 1: Aerial photograph of the plant

  • Location information

    Address, plant tour, employees

    Bosch Thermotechnik GmbH

    Lollar plant

    Justus-Kilian-Straße 1

    35457 Lollar


    Tel.: +49 (6441) 418-0

    Contact person for plant tours:

    Phone +49 (6441) 418-0


    DIN ISO 9001, DIN ISO 14001

    Employees: ca. 1.200

  • Products

    Key products manufactured at the plant

    - Cast heating boilers

    - Atmospheric special gas boilers

    - Oil/gas fan boilers (all in an output range from 9 to 1,200 kW)

    - Controlling devices

    - Burners

  • History

    Milestones in the history of the plant


    Foundation as a charcoal furnace plant under the name of "Hedwigshütte“


    The plant is taken over by Buderus and renamed "Main-Weser-Hütte"


    The first coke furnace in the central Lahn region is taken into operation in Lollar


    Construction of a foundry, which gains an excellent reputation for the production of stoves


    Start of industrial mass production of boiler sections in Germany in the foundry of Main-Weser-Hütte


    The first radiator plant on the European continent is built in Lollar


    After the furnace operation is discontinued, Main-Weser-Hütte becomes a special plant exclusively for heating products


    Start-up of a “trial facility” - the predecessor to today’s R&D unit


    Modernisation and replacement investments


    Erection of the first moulding line (assembly line production) in the radiator production unit


    Start of the production of controlling devices in Lollar


    Manufacturing conditions in the foundries are improved significantly


    Extensive modernisation investments – The five millionth sectional boiler is produced at the Lollar plant in 1998


    150th anniversary of the Lollar plant


Location information, products and history: Lollar 2

Lollar 2: The plant of Bosch KWK Systems

  • Location information


    Bosch KWK Systems GmbH

    Justus-Kilian-Straße 29-33

    35457 Lollar


    Tel.: +49 (6406) 9103-0

    Fax: +49 (6406) 9103-30


  • Products

    Key products manufactured at the plant

    - CHP units

    - ORC systems

    - Gas purification units

    - Exhaust gas treatment systems

  • History

    Milestones in the history of the plant

    Bosch KWK Systeme in Lollar is Bosch Thermotechnik’s centre of excellence for combined heat and power (CHP) units. For almost 30 years, the company has been developing and manufacturing standardised or customised CHP units for both biogenic gases and natural gas. This means that Bosch KWK Systeme draws on decades of experience in manufacturing cogeneration plants.


    Helmut Ziegler takes over a metalworking shop with three employees and establishes Ziegler Metallverarbeitung. The resources generated are used for new ideas: the foundations for Köhler & Ziegler are laid.


    In summer 1981, Harald Köhler approaches Helmut Ziegler with the idea of manufacturing stationary CHP units from mass-produced engines. Building on the combined engineering, metalworking and electrical engineering expertise, the first gas CHP unit (a pilot installation called “Erlkönig”) is built for the Lich sewage treatment plant.


    The success of the pilot plant leads to the foundation of Vertriebsgesellschaft Köhler & Ziegler OHG. Ingenieurbüro Köhler is responsible for planning and engineering, while Ziegler Metallbau is in charge of design and construction.


    Köhler & Ziegler wins a research contract from the federal state of Hessen.

    In 1984, Köhler & Ziegler’s catalyst measurement and test bench makes an important contribution to the development of the legal rules and regulations for the definition of pollution limits, Germany’s “1/2 TA Luft” (clean air act).


    Acquisition and reconstruction of a new site at Auweg in Lollar to expand the office and production space to 1,500 square metres.


    Expansion of the total plant area to 2,400 square metres.


    Certification to ISO 9001 and EU Eco-Audit.


    After intensive development work and bench testing, Köhler & Ziegler achieves higher outputs for all machines, which means increased performance for the same money. The first 1,010 kW CHP unit is installed at a sweets manufacturer and reduces the company’s annual carbon emissions by 5,000 t. Köhler & Ziegler CHP units additionally offer the possibility of air-conditioning.


    The first generation of the Köhler & Ziegler ORC system is taken into operation. A new container concept is born. All the components of a CHP unit are built into a compact container. Installed at biogas digesters, these units allow for optimised coordination of biogas production and biogas utilisation.


    The new production hall of Plant II comprises 500 square metres of office space and staff facilities as well as 2,300 square metres of production space. Its total area of 12,500 square metres offers much room for technology and innovative ideas. The new plant increases the total production space of Köhler & Ziegler to 4,700 square metres.


    Since August 2008, Köhler & Ziegler has supplied Buderus, a brand of Bosch Thermotechnik GmbH, with CHP units in the small and medium output range. The product range includes CHP units in five module sizes (19, 50, 70, 140 and 240 kW).


    In March 2010, Köhler & Ziegler Anlagentechnik GmbH is taken over by Bosch Thermotechnik GmbH, the leading European supplier of heating products, who holds strong positions in all important market segments. The acquisition makes Köhler & Ziegler a wholly-owned subsidiary of Bosch’s Thermotechnology Division.


    Köhler & Ziegler Anlagentechnik GmbH is renamed Bosch KWK Systeme GmbH. As a result, the company benefits even more than before from Bosch’s good reputation and brand awareness. The administrative departments move to Justus-Kilian-Straße.


    Since April 2012, Bosch KWK Systeme has sold its plants under the Bosch brand instead of the Köhler & Ziegler brand. The well-known product range of Köhler & Ziegler is retained and expanded significantly.


    30 years of experience in CHP business:

    In 1981, engineer Harald Köhler moved up to the young entrepreneur with the idea to build stationary combined heat and power units out of large series engines. Helmut Ziegler was quickly excited - and with the combined knowledge of engineering, metal and electrical engineering, the first gas cogeneration unit was built as a pilot plant "Erlkönig". The success of this product lead to the foundation of the sales company Köhler & Ziegler OHG in February 1983.

    On 1 January 2013, Dr.-Ing. Jürgen Sterlepper is a new member of the management board. He heads the company together with Ralf Klein (Chairman of the Board of Management) and Ulrich Inderthal.

    Helmut Ziegler leaves the Management Board of Bosch KWK Systeme GmbH to 31 December 2012. The founder of Köhler & Ziegler Anlagentechnik GmbH will provide Bosch KWK Systeme GmbH with considerable experience and knowledge in a consulting capacity.