What is the purpose of a low limit control in a combination system?

The purpose of a low limit control in a combination system is primarily to assure a constant supply of hot water. This control is designed to monitor the water temperature within the system and ensure that it does not drop below a predefined threshold. When the temperature falls below this limit, the system activates to maintain the desired water temperature, ensuring that hot water is readily available for use when needed.

By continuously monitoring and maintaining the temperature, the low limit control plays a crucial role in the efficiency and convenience of the hot water delivery system. Not only does it ensure comfort by providing a stable supply of hot water, but it also contributes to the overall safety of the system by preventing water temperatures from dropping too low, which could lead to other operational issues.

The other options, while they may address different aspects of water system management, do not capture the primary function of the low limit control in the same way.