Why is a low limit incorporated in hot water tanks supplying both domestic hot water and space heating?

Incorporating a low limit in hot water tanks that supply both domestic hot water and space heating is essential for ensuring a constant supply of domestic hot water. This low limit helps maintain a minimum temperature within the tank, which prevents the water from falling below a certain threshold. If the temperature drops too low, the water may not be sufficiently heated for immediate use, leading to potential discomfort and inefficiencies in heating when hot water is needed.

By keeping the water at a stable, higher minimum temperature, the system is better equipped to deliver hot water promptly whenever it is required, thus improving user experience and efficiency in both domestic applications and space heating.