they are not inter change able . they must be in hard contact to take the temp of the tank, also the right size for the amps . are you sure the t;sat the problem , how did you rule out blown fuse, and or element.
The water heater was still running, but the water was coming out scalding hot and the temperature limit switch kept tripping. I assume that meant the issue wasn't a blown fuse (I don't know much about this stuff so maybe that's not true?). Based on internet research, I first checked for both heating elements to see if either or both had shorted, but everything read normal on the multimeter. Some sites recommended checking the pressure relieve valve. I haven't yet, but probably should. Yesterday I bought a universal thermostat set and replaced both the upper and lower thermostats. As of this morning, everything was okay. As soon as I get home I'm gonna check the water again.