[Almost Retired]

I got a service call to check out a hot water tank that was blowing fuses.

have you fixed it yet ?
come on we worked hard to help you
let us in on the victory celebration LOL

 

[joe-nwt]

Most of my experience with water heaters tells me that the upper hi limit trips because the bottom control doesn’t shut off. So it’s only after the top thermostat is satisfied and the bottom has run long enough with no water usage that you see a trip.

Most likely culprit.

 

[macmikeman]

Around here , the solar tanks seem to always trip the red button during summer months. Then when winter comes around (still around 76 degrees outside all day,) and it starts raining for 6-10 days straight, like last month, I get ten call outs for water heater issues. Almost never tripping circuit breakers though, unless one of the elements breaks down inside the tank, which I have not seen in any of the above replies. Always check the elements on the tank when you get called out for water heater problems. That's a potential life saving issue. They can become a high resistance fault to ground that doesn't trip out the circuit breakers and possible to shock people using sinks or showers .