What function does a booster water heater serve?

A booster water heater is specifically designed to raise the temperature of the regular hot water supply to meet specific requirements, which is crucial in situations where higher temperature levels are necessary, such as in commercial food service operations or for certain plumbing fixtures. This type of heater is particularly useful for ensuring that the water being supplied is at an appropriate temperature for sanitization purposes.

In many applications, the standard hot water supply may not reach the temperatures needed for specific tasks, such as dishwashing or medical applications. A booster water heater effectively solves this issue by elevating the water temperature to meet these critical needs.

The other options present functions that a booster water heater does not fulfill. For instance, maintaining a constant temperature might relate more to a traditional hot water storage system, while reducing water pressure and filtering impurities are not intrinsic purposes of a booster heater. Thus, it is clear that the core function of a booster water heater is to elevate the temperature of the existing hot water supply.