Abstract: A heat exchanger that includes a portion for heat exchange with gray water, a portion for heat exchange with clean water, the heat exchanger being arranged to transfer heat between the gray water heat-exchange portion and the clean water heat-exchange portion during a distribution of water and thereby heat a feedwater to a first temperature, wherein the heat exchanger includes a first heating means arranged to achieve the heating of the feedwater, for heating the feedwater to a second temperature, and wherein the heat exchanger includes a second heating means arranged to keep the clean water heat-exchange portion at a temperature greater than or equal to the first temperature during a period without water distribution.

Abstract: A domestic hot water distribution device includes a supply water inlet, a waste water collector and means for heating the supply water in order to produce domestic hot water from the heat contained in the waste waters The heating means include thermo-electric modules laid out for operating heat transfer from the waste waters to the supply water to be heated.