Operation through heating control for 2-point, 3-point or continuous control. Selection of characteristic line is linear or parallel. Two-piece body made of selfextinguishing plastic. Plastic console and brass union nut for valve installation. Working condition can be directly switched, automatic adjustment of valve lift. Code switch for selection of characteristic line and running time. Gearbox for positioning of valve and adjustment of hand wheel. Vertical and horizontal mounting is possible, inverted installation is not possible.