Abstract: An oven, which maintains food at a low temperature to preserve its properties for subsequent unattended cooking at high oven temperatures, is cooled and heated by a flowing liquid thermal exchange fluid which is cooled and heated by flowing through thermal sources separate from the oven. Within a food processing compartment of the oven, heat is exchanged between an enclosed chamber heat exchanger and the food by air convection.In a preferred embodiment, the oven is one of a plurality of domestic appliances similarly heated and cooled by a liquid thermal exchange fluid. The oven and the other appliances share in common an assembly of thermal reservoirs which provides thermal exchange fluid under pressure at substantially the temperatures of the thermal reservoirs which include a hot and a cold reservoir.