This research performs thermal analysis of the central heating's radiator by the final elements method manner using Cosmos/m2.6, Where it was designing a three dimensional model of the radiator with engineering specifications that mimic one of the used radiators .Then apply a convection simulates the role of the mediator heating used and ambient temperature for concluding the mathematical behavior of thermal gradient within the radiator. Research proposing a control system depends on adjusting the intermediary of heating inside the radiator, through the installation of flow control valve which works by D.C motors at the entrance to each radiant. The research shows the inability of depending on controlling system which uses the PI controller in building a suitable control system, Because the difficulty of receiving signals from analog temperature sensor that reflect the constant readings of room temperature which makes the response of control valve for signals slow, Thus makes the use of PI unhelpful of the economic and technical side.