In this paper, ferrofluid flow in a closed cooling loop without any mechanical pump has been simulated. The flow of the ferrofluid in the closed loop is resulted from applying a non-uniform magnetic field and the thermo-magnetic effect of the ferrofluids. The ferrofluid consist water and different volume fractions of iron oxide nanoparticles with nanoparticle diameter of 13nm. The two phase mixture model and the control volume technique have been used in the present study. The applied non-uniform magnetic field is resulted from an electromagnetic solenoid and the steady and also the transient modeling of the flow in the cooling loop from start point (stagnant ferrofluid in loop) have been carried out. The obtained results show that by applying magnetic field and also by taking advantage of temperature dependent property of the magnetic susceptibility, a flow of ferrofluid is created in the loop and by increasing the heat input (heater power) in the loop, the flow rate in the loop is increased. Moreover, the results show that by having a cold source (for rejection of produced heat) with higher constant temperature, the flow rate in the loop increases. Furthermore, the flow rate in the cooling loop is increased as the volume fraction of the nanoparticles in the base fluid increases. The mentioned cooling loop can be used in the electronic cooling systems.