Product review (5 stars): Would recommended purchasing a tub thermostat if this one keeps tripping
This is the third one I've had to replace within a year.  After a lot of troubleshooting I found that the other thermostat had failed (wasn't limiting the temperature at all so heating element didn't shut off), which caused higher than rated temperatures and kept popping this one.

Would recommended purchasing a tub thermostat if this one keeps tripping.