Look towards the warranty as a guide. Panamax, and others, offer lifetime warranties, which could imply that it need not be replaced. But be careful, the warranty could specify a voltage spike limit or duration in milliseconds, which could mean that even a new unit may not protect you in some circumstances.
What impact does repeated overvoltages have over the course of years? The best way to answer your question is to contact Panamax and see if they still back it up. I doubt they'll steer you to an unecessary purchase.
What impact does repeated overvoltages have over the course of years? The best way to answer your question is to contact Panamax and see if they still back it up. I doubt they'll steer you to an unecessary purchase.