Abstract: A system to heat liquids. A liquid, such as water, is heated by microwave energy. A housing assembly comprises a plurality of magnetrons, which may be arranged in a vertical manner. Conduit, which allows the water to flow therethrough, is secured within the housing. Incoming cold water enters the housing assembly through a first one-way valve and the conduit. The conduit coils within the housing assembly and the water is heated within the conduit by the magnetrons when producing microwave energy. Outgoing hot water exits the housing assembly through the conduit and a second one-way valve, which accommodates the flow of hot water therethrough. The magnetrons are controlled by thermostats, which maintain an outgoing water temperature at a predetermined level.