I have heat tape on the water line under my mobile home. Do I need to replace it every few years, or should it be good indefinitely? I would hate my water line and meter to freeze just because the tape wore out. I would rather be proactive, if this is a risk.
After you have unplugged it, or otherwise disconnected the power to it for the season, I would carefully check the entire length of it, inch by inch, for any physical damage, whether from rodents, rubbing on a tight bend, or anything like that. As long as the plug and the cord itself is in good shape, I would consider it "good to go".