Theodor Heimeier Metallwerk

Theodor Heimeier Metallwerk is a German heating-technology company that develops, produces and globally distributes heating fittings and valves. It was founded in 1928 in Lippstadt by the engineer Theodor Heimeier, who initially set up a production line for semi-finished and finished parts, pressing and casting brass components for general valve manufacturing. After the founder's death in 1946, the firm increasingly specialised in heating-system valves during the 1950s, began building a red-brass foundry in 1952, and moved to Erwitte, about 6 km away, in 1965. The company introduced the Mikrotherm radiator regulating valve, which in 1969 was complemented by a liquid-filled thermostatic valve. The global oil crisis sharpened attention to energy-conscious systems and paved the way for growing demand for thermostats and heating fittings. In 1980 the company established sales agencies in Canada, Australia, Japan and the Far East as well as in the USA; production facilities in Erwitte have been continuously expanded since 1960. In 1995 the company was acquired by the IMI plc group. Today the business operates as IMI Hydronic Engineering Deutschland GmbH, headquartered in Erwitte, North Rhine-Westphalia, and is part of the IMI plc group. It is a heating-technology company that develops, produces and globally distributes heating fittings. The thermostatic valve forms the core of the company and has been continuously developed; there are currently 120 different valve bodies and 40 different thermostat heads, including valves for reverse flow direction, reverse action, particularly low-resistance valves, and designs for all types of radiator connection and authority models. In addition to setting positions 1–5 for room temperature, the thermostat heads have visual markings for frost-safe operation and night setback as well as tactile grooves that make operation easier for the visually impaired. Adapter pieces allow thermostat heads from competitor products to be fitted. Other products include thermal actuators for underfloor heating and for heating, ventilation and air-conditioning systems, room thermostats, special fittings, balancing valves for hydraulic balancing and overflow valves. With the advent of data transmission, radio and bus systems were developed. As of 7 October 2024, IMI Hydronic Engineering renamed itself IMI, with a new corporate appearance including a purple logo replacing the previous orange colour scheme. At the same time the new Climate Control business sector was created, dedicated exclusively to the HVAC field. Climate Control brings together the brands IMI Pneumatex, IMI TA and IMI Heimeier. The new structures allow stronger bundling of expertise and the development of efficient solutions for indoor climate and heating and cooling applications. By merging the business areas under a unified identity, IMI intends to strengthen its guiding principle "Breakthrough Engineering for a better world" and to act as a system partner for hydronic water circuits. The updated logo and new colours are visible on digital channels, at events and on product labelling; new product packaging is being introduced gradually to support sustainability goals. The company employed 380 people in 2025, including 10 apprentices.

Theodor Heimeier Metallwerk was founded in 1928 in Lippstadt by the engineer Theodor Heimeier. He initially established a production line for semi-finished and finished parts, producing pressed and cast brass parts for general valve manufacturing. After the founder's death in 1946, the company increasingly specialised in heating-system valves during the 1950s. In 1952 it began building a red-brass foundry, and in 1965 the company moved to Erwitte, about 6 km away. The Mikrotherm radiator regulating valve was introduced to the market and in 1969 was complemented by a liquid-filled thermostatic valve. The global oil crisis sharpened attention to energy-conscious systems and paved the way for growing demand for thermostats and heating fittings. In 1980 the company was therefore able to establish sales agencies in Canada, Australia, Japan and the Far East as well as in the USA; production facilities in Erwitte have been continuously expanded since 1960. In 1995 the company was acquired by the IMI plc group. In 2025 the company employed 380 people, including 10 apprentices. As of 7 October 2024, IMI Hydronic Engineering renamed itself IMI, with a new corporate appearance including a purple logo replacing the previous orange colour scheme. At the same time the new Climate Control business sector was created, dedicated exclusively to the HVAC field. Climate Control brings together the brands IMI Pneumatex, IMI TA and IMI Heimeier. The new structures allow stronger bundling of expertise and the development of efficient solutions for indoor climate and heating and cooling applications. By merging the business areas under a unified identity, IMI intends to strengthen its guiding principle "Breakthrough Engineering for a better world" and to act as a system partner for hydronic water circuits. The updated logo and new colours are visible on digital channels, at events and on product labelling; new product packaging is being introduced gradually to support sustainability goals.

• 2025

  Company employed 380 people, including 10 apprentices.

• 2024

  IMI Hydronic Engineering renamed itself IMI on 7 October; new Climate Control sector created, bringing together IMI Pneumatex, IMI TA and IMI Heimeier.

• 1995

  Acquired by the IMI plc group.

• 1980

  Established sales agencies in Canada, Australia, Japan and the Far East as well as in the USA; 50,000 fittings per day left the foundry.

• 1969

  Liquid-filled thermostatic valve, for which a patent was applied, complemented the Mikrotherm valve.

• 1965

  Moved to Erwitte, about 6 km away.

• 1959

  Mikrotherm regulating valve formed the core business.

• 1952

  Began construction of a red-brass foundry.

• 1946

  Death of founder Theodor Heimeier.

• 1935

  Began production of gas shut-off valves.

• 1928

  Founded in Lippstadt by engineer Theodor Heimeier.

Premium HVAC solutions focused on optimal comfort, energy efficiency and connectivity; a system partner for hydronic water circuits under IMI's Climate Control sector.

• Mikrotherm radiator regulating valve

  Introduced in 1959 as the core business; a radiator regulating valve.

• Liquid-filled thermostatic valve

  Developed in 1969 and patent-applied; complemented the Mikrotherm valve.

• Thermostatic valve range

  Currently 120 different valve bodies and 40 different thermostat heads, including reverse flow, reverse action, low-resistance and authority models.

• Thermal actuators

  For underfloor heating and for heating, ventilation and air-conditioning systems.

• Room thermostats

  Room thermostats and special fittings.

• Balancing valves

  Strang regulating valves for hydraulic balancing and overflow valves.

• Radio and bus systems

  Developed with the advent of data transmission.

1. 1Welcome | IMIclimatecontrol.imiplc.com
2. 2Who We Are | IMIclimatecontrol.imiplc.com
3. 3IMI TA | IMIclimatecontrol.imiplc.com
4. 4IMI Flow Design | IMIclimatecontrol.imiplc.com
5. 5Theodor Heimeier Metallwerkwikidata.org
6. 6Theodor Heimeier Metallwerkde.wikipedia.org