A fluid heating system may be installed for residential and commercial use, and may deliver fluid at consistent high temperatures for cooking, sterilizing tools or utensils, hot beverages and the like, without a limit on the number of consecutive discharges of fluid. The fluid heating system is installed with a tankless fluid heating that includes an inlet port, an outlet port, a drain port, at least one heat source connected with the inlet port, and a valve manifold connected to the at least one heat source, the drain port, and the outlet port. A temperature sensor is downstream of the at least one heat source and connected to the valve manifold. The valve manifold is operated so that an entire volume of a fluid discharge from the fluid heating system is delivered at a user-specified temperature (including near boiling fluid) on demand, for every demand occurring over a short period of time.