摘要:The paper represents the mathematical model for diagnostics of the corrosion protection potential for the electric water heaters (EWH). The research objectives are the problem of determining the EWH corrosion protection technical condition during its operation. The EWH corrosion protection diagnostics is based on the mathematical model of the corrosion protection potential for EWH. The model is based on the nonlinear equivalent circuit which is modelling the nonlinear impedance of the corrosion cathodic protection. In the development of the mathematical model the authors carried out experimental measurements of the impedance for the EWH body fragment. The obtained experimental results show that mathematical model includes the fractional integrating elements. By using of the experimental results the expressions of the impedance, the impulse response is obtained. The methodological approach to increasing the reliability of the EWH corrosion protection diagnostics has been proposed, in terms of the multi-parameter diagnostics, by applying the EWH corrosion protection impedance model.