De Dietrich 95363353 setting thermostat 30-90C

This is a setting thermostat with an adjustable range from 30 to 90 °C, listed under the De Dietrich brand with catalogue article 336.805.012 and manufacturer codes 95363353 / 336.805.012. Parts of this type are mechanical temperature switches that act directly: they open or close an electrical circuit when the sensed temperature reaches the set point. In a boiler or burner system, such thermostats are used as control thermostats (e.g. to regulate flow temperature) or as limit thermostats (to cut off the burner if a safe maximum is exceeded). Unlike NTC sensors that report a continuous value to the control board, these thermostats provide a simple on/off signal. When selecting a replacement for a thermostat of this class, the key parameters are the adjustable temperature range (here 30–90 °C) and the reset type – manual lockout or automatic return. The switching differential (hysteresis) also matters, though it is not stated for this specific article. The sensing element may be a capillary bulb, a bimetal strip or a rod, and the probe form (immersion, clamp-on or insertion into a pocket) must match the original installation to ensure correct thermal contact. A clamp-on thermostat, for example, requires clean, flat pipe surfaces and heat-conductive paste for accurate reading. Typical failures in mechanical thermostats include drift of the switching point due to fatigue of the bimetal or loss of charge in a capillary system, as well as mechanical jamming or poor electrical contact. If the burner cycles erratically, fails to reach the set temperature or goes into safety lockout, the thermostat should be checked. When replacing, always confirm the set range and, if possible, test the switching point against a known thermometer. The part is identified by the codes above; no further compatibility data is supplied for this article.