I recently installed a Rheem Gladiator 5500w water heater whereas the old one was a 4500w. My home was wired with 10ga wire and a 25A breaker. I saw the draw on the heater was at 22.5A and I asked the installer whether the 25A breaker should be replaced -- he didn't think it was a problem. A week later my water heater issued an alert indicating a potential problem with the control board. The breaker never tripped, so it doesn't seem there would have been too much voltage or overheating of the wires -- in my mind if the breaker were too small the only thing that would happen is it would keep tripping if the draw were too high. I called Rheem and they advised that the heater had to be installed with a 30A breaker and advised me this may void the warranty. I swapped the breaker out for a 30A and the alert cleared, and called them back and advised them that the situation had resolved, since I wanted their records to reflect that. Then a week later I got a new A114 alert indicating overheating of the panel (A114* : Safety Temperature Protection : Replace water heater). So my question is, could use of a 25A breaker where a 30A breaker is required damage the circuit board on the water heater in any way, esp. since the extra capacity is for overcurrent anyway? My feeling is they may try to avoid warrantying the unit but I don't think having the 25A breaker would have caused damage to it. Thoughts?