A household dishwasher includes a wash container for holding dishes to be washed and a fill reservoir attached to the wash container. The fill reservoir is filled with fresh water from a fresh water network, and a quantity of fresh water required for the wash sub-cycle is removed from the fill reservoir and feed into the wash container. A heat pump includes an evaporator which is thermally coupled to the fill reservoir to extract heat energy from stored fresh water, and a condenser via which heat energy is fed into an interior space of the wash container. Disposed between the interior space of the wash container and an interior space of the fill reservoir is a single-layer or multilayer insulation material system to reduce a heat flow from the wash container.