A heat accumulator, in particular a latent heat accumulator has an inner jacket arranged to surround an accumulator core and an outer jacket surrounding the inner jacket so as to form an insulation chamber therebetween, two conduits extending from the insulating chamber outside and forming a supply conduit and a return conduit for a heat transporting medium and elements for counteracting heat losses and associated with the conduits, each of the conduits in its course having a conduit interruption and being provided with a thermal insulation in the region of the conduit interruption so as to form the heat losses counteracting elements.