Abstract: A heating system includes a first fluid circulation system having tubing for conveying fluid, a pump for moving the fluid through the tubing of the first fluid circulation system, and a microwave system that heats the fluid passing through the tubing. The amount of fluid circulating in the first fluid circulation system approximates less than a gallon. A second fluid circulation system has tubing for conveying fluid and a pump for moving this fluid through the tubing of the second fluid circulation system. A heat exchanger, connected to the tubing of the first fluid circulation system and to the tubing of the second fluid circulation system, the heat exchanger transfers heat from the fluid in the first fluid circulation system to the fluid in the second fluid circulation system.