What' s the life span of power surge protections?

No surge protector will help if lightning strikes between the power-pole transformer and the power lines running to your house.

Surge protectors work for voltage anomalies, but WILL NOT PROTECT EQUIPMENT FROM A LIGHNING STRIKE!!! Unplug [don't just throw the circuit breaker] your gear if there is electrical storm activity in your area!

Good point, Mt10425. You did check one a while to make sure your brickwall not cracking up, didn't you? Foundation repairs could be expensive.

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.