What is the maximum temperature of water in a gravity hot water system?

In a gravity hot water system, the maximum temperature is typically capped at about 77 degrees Celsius. This is primarily due to safety and efficiency considerations. At temperatures higher than this, there is an increased risk of scalding and potential damage to the system components. Additionally, maintaining water at this lower temperature helps prevent issues such as excessive pressure build-up or the deterioration of the pipes and fixtures over time.

In contrast, the other temperature options exceed this safe threshold for a gravity hot water system, making them less suitable for such applications. This maximum is designed to ensure comfort while minimizing risks in residential settings.