Ok, so heres the deal.....Im working on an electric hot water heater. The problem is the hot water heater keeps popping the reset. You have to press the reset button when you want hot water. It will then heat up. I dont think its the heating element as the water DOES get hot once you reset it......so does that mean its the theromstat?
The reset button is part of the thermostat assembly , right ?
Replace it . I had the same problem some years back and changing out the t-stat fixed it .
it could be a number of things.
some diagnosing tips can be found here at this link:
http://www.waterheaterrescue.com/pages/WHRpages/English/Troubleshooting/Tanklets/electric-water-heater-issues.html