How far must the tip of the thermocouple be positioned in the pilot flame?

The tip of the thermocouple must be positioned within the range of 3/8" to 1/2" in the pilot flame to ensure proper functioning and accurate readings. This positioning allows the thermocouple to effectively sense the flame's temperature and generate sufficient voltage to maintain the safety of the system. If the thermocouple is placed too high, it may not receive the adequate heat required for operation, leading to a potential failure to keep the gas valve open. Conversely, if it is positioned too low, it may not accurately register the flame's temperature, possibly resulting in unsafe conditions if the flame goes out. Therefore, placing it within the specified range optimizes safety and the thermocouple's accuracy in gas appliance operations.