Let us introduce ourselves

We have been combining our technical expertise in thermowell production with day-to-day applications experience to create unique know-how since 1978. With the aid of more than 50 employees, we currently produce over 1.7 million thermowells and sensor wells in fully automated mass production and individual small batches at our site in Lollar, Central Germany.

Constant upgrading is a priority for us, especially in relation to environmental efficiency and maximum delivery reliability.

Ziegler Bild weltweit


Know-how acquired over time for our clients.

Renowned manufacturers in the HVAC systems and plant engineering sectors and building technology  use our Ziegler protective wells the world over. We provide our clients with high-quality, reliable assistance with a bespoke service.

Ziegler has a strong international focus.

Ziegler Bild Qualität


100% inspection to ensure compressive strength and leak-tightness

We submit all thermowells to a pressure test and inside diameter check. We verify other parameters during sample checks. 
The checking process is documented in an inspection record. This ensures that materials and activities can be traced in line with ISO 9001:2015.

This ensures optimum quality for your thermowells.

Bild Umwelt

Environmentally aware

Nature-conservation approach to production.

Our environmental management system allows us to protect the environment and ensure sustainability. Our measures include heat recovery and environmentally friendly power generation thanks to the use of combined heat and power generation units. We have formed part of the "Umweltallianz Hessen" regional environmental alliance since 1998 and are also certified to ISO 14001:2015.

We ensure energy efficiency to protect the balance of nature.

Ziegler Inhaber Andreas Ziegler


A successful family enterprise since 1978

Under the leadership of owner Helmut Ziegler, our company launched its first mass production run of thermostat thermowells for the heating industry just one year after the company's foundation. His son Andreas Ziegler has been overseeing the quality and environmental management system since 1998 and took over as CEO in 2012

Growth is moving Ziegler thermowells forward into a successful future.

Quality and standards

Fully automatic series and individual efficiency.



  • Helmut Ziegler takes over metalworking shop and its three employees from Konrad Junk, providing general metalworking and mass production for the roofer wholesale trade.  A year later, he launches mass production of thermostat thermowells for the heating industry.


  • Systems are upgraded with the introduction of fully automatic thermowell and sensor well production. This automation transforms the company into a European market leader in thermostat thermowell and sensor well production. Demand increases.


  • The acquisition of new welding machines allows manufacturing to increase to 1.3 million protection wells per year. Andreas Ziegler, a qualified engineer, takes over a year later. With a workforce now increased to over 50, the company is set to continue as an owner-operated enterprise.