De Dietrich 95363366 safety thermostat 105C

This safety thermostat is a mechanical limit switch designed to open its contacts when the sensed temperature reaches 105°C. In a boiler, such a device is typically wired in series with the burner control safety circuit. If the water temperature exceeds the set point, the thermostat opens and interrupts power to the burner, forcing a lockout or shutdown until the temperature drops and the thermostat resets. The reset may be automatic or manual depending on the specific model; for a safety thermostat, manual reset is common to prevent automatic restart after an overtemperature event. Parts of this type are selected primarily by their switching temperature and the reset mode. The probe form—immersion, clamp-on, or capillary—must match the installation point on the boiler or pipe. When replacing a safety thermostat, verify that the switching temperature is identical and that the probe length or bulb fits the existing pocket. Also check the electrical rating (voltage and current) and the contact configuration (normally closed for safety thermostats). Do not assume compatibility based on brand alone; always compare the physical dimensions and the reset mechanism.