At what temperature does a hot water heater's temperature relief valve typically activate?

The temperature relief valve in a hot water heater is designed to activate at a pre-set temperature to ensure safety and prevent excessive pressure build-up within the tank. The correct activation temperature for most hot water heaters is typically around 99°C (210°F). This temperature is significant as it allows the valve to release steam or water to reduce pressure if the temperature exceeds this level, thus preventing potential hazards such as tank rupture or explosion.

The specific temperature of 99°C is chosen because it is just below the boiling point of water at standard atmospheric pressure (which is 100°C or 212°F), allowing for a safety margin. This prevents the heater from reaching dangerous pressure levels that can occur at higher temperatures.

Understanding this activation temperature is crucial for maintaining safety standards in residential and commercial water heating systems. Regularly testing and inspecting the temperature relief valve ensures its proper functioning and the safety of the hot water system.