Your hot water comes from a hot water heater that is located either inside in a closet or outside in the crawl space. They can be electric or gas, with a tank or tankless. The hot water tank holds water that is constantly heated to keep water hot. Depending on the brand, hot water heaters may have a lifetime of 5 to 10 years. It is usual for hot water heaters to leak toward the end of its life. If your hot water heater is inside your home, please periodically check the bottom area of the heater for leaks. If leaks are left unchecked, there is potential for extensive water damage. If you stop getting hot water, if it is a gas heater, make sure you have paid your gas bill. For electric heaters, make sure that the circuit breaker has not tripped. Report the problem to maintenance as soon as possible. Delay in reporting might prevent you from taking a hot shower.