De Dietrich 95363314 thermostat de sécurité 110C L3000

This is a De Dietrich safety thermostat, catalogue article 336.805.020 and manufacturer code 95363314. The part name indicates a nominal switching temperature of 110 °C. It is a mechanical limit thermostat, meaning it acts directly on the safety circuit without passing through the control board. In a boiler, such a thermostat is typically fitted to the flow pipe or the heat exchanger and cuts the burner if the water temperature exceeds the set point, providing a hard safety override against overheating. When selecting a replacement safety thermostat of this type, the key parameters are the switching temperature, the reset mode (manual or automatic), and the mechanical configuration — immersion pocket, capillary bulb, or clamp-on contact. The part number suffixes often distinguish these variants. Before installation, verify that the probe form and the connection method match the original. A manual-reset type requires a technician to press a button to re‑enable the burner after a trip, which is common for safety limits. If the old thermostat is drifting (causing premature cut‑out or no cut‑out at all), replace it with a part of the same temperature class and reset type. Also check the cable condition and the contact between a clamp‑on probe and the pipe, as poor thermal contact leads to delayed response.