De Dietrich 95363355 sensore di corrente 85C

A De Dietrich draft sensor with an 85 °C switching point is a component that belongs to the category of mechanical thermostats or limit switches used in the flue gas path of a boiler. Parts of this type monitor the temperature of the exhaust gases and are typically wired into the safety circuit of the burner control. If the flue gas temperature exceeds the set point, the sensor opens the circuit, triggering a safety shutdown or preventing the burner from starting until the temperature drops below the reset threshold. The sensor is normally closed and opens at 85 °C; the exact reset behaviour (automatic or manual) must be confirmed from the original specification. When selecting a replacement, the critical parameters are the switching temperature (85 °C), the electrical rating (voltage and current), the type of mounting (often a clip or flange that fits into a flue gas stub), and the cable length and connector if applicable. For this specific article, only the switching temperature and the brand are given; the probe form, body dimensions, and electrical connection details are not stated in the available data. Always compare the physical shape and the electrical connector of the existing sensor against the replacement to ensure it will seat correctly in the boiler flue. Typical failures for such sensors include a drifting switching point due to ageing or soot contamination, a broken internal bimetal strip, or a shorted or open circuit in the cable. During troubleshooting, measure continuity across the terminals at room temperature (should be closed). If the sensor fails open even when cold, replace it. Also inspect the mounting location for corrosion or deposits that could have altered the heat transfer to the sensing element.