An example method for monitoring the operation of a metal-oxide varistor (MOV) may involve monitoring an operating value of at least one parameter of the MOV using at least one sensor. Further, the method may involve determining, using one or more processors, that a difference between the operating value and a reference value corresponding to the at least one parameter satisfies a predetermined threshold condition corresponding to the at least one parameter. And the method may involve responsive to determining that the difference between the operating value and the reference value satisfies the predetermined threshold condition, transmitting a notification indicative of a potential failure of the MOV to at least one device.