Combination Thermal Stores are manufactured as steel pressure vessels, either with an integrated hot water storage tank, or with a heat exchanger for instantaneous hot water heating. Such a thermal store turns into a sophisticated unit consisting of a series of solutions that together bring significant energy savings, saving also the environment. Some tanks are fitted with a separating metal sheet that enables better thermal layering inside the tank; sufficient hot water supply even when the lower section is exhausted by heating; automatic auxiliary energy sources switching, separate for heating and separate for DHW after all heat is exhausted from the thermal store.