A14. A point-of-use water heater is a very small water heater, either a mini-storage tank or a small tankless model, that is designed to be installed at the point of use, thereby eliminating a long pipe run. They are mostly sized to supply hot water to one specific application, usually a sink. A common application is a remote sink, such as a bathroom in an office building or a service station. Another common application is for distant sinks in the home that typically take too long to receive hot water.