The reliability and quality of electrical power networks are affected by the occurrence of electrical faults. In this paper, we propose a novel method to identify the occurrence of faults in distribution networks, based on impedance measurements performed at the central distribution office. The measurements can be performed using PLC modems that belong to the energy metering infrastructure. The fault is detected by means of continuous impedance monitoring and afterwards its distance from the central office is estimated using the same measurement traces, without requiring additional information. Different type of faults are tested, and the effect of the measurement bandwidth and the electrical noise on the measurement is also assessed.