The project combines an elder project which was created two years before. This product is a solution of a complete closed loop temperature control concerning a problem which appears especially at big buildings. If suddenly, there is a high amount of warm water needed, the challenge is to deliver all water supplies with warm water of a certain temperature. This is not very effortless to implement because of long pipelines and because the insulation of them is not perfect, a part of the heat get lost. If there is no warm water consumption for a longer period the water is cooling down in the pipes.Our target is to solve this problem.Up to now a closed loop control with reference to ours was only possible by using expensive single components. So we will lower the procurement costs.