Under-sink water heater. Repairable or replace?

[nuyorican]

Got a Redring under-sink water heater in my workplace. It cut out recently and tripped the electrics. I had a look at it and noticed it was leaking. Nipped up the loose nut, turned it on and it was good again, for a few days but it's tripped again, no leak this time. Left it off for a while, tried it again and now it's working again...

Anything obvious to try before I replace it? They're reasonably inexpensive so I'm not about to go tearing it apart and breaking out the soldering iron. Maybe the leak got into it and it will keep tripping until it's fully dried out? Or perhaps the link is a red herring. It was installed about five years ago but no idea on whether it was new as I didn't do it myself.

Cheers