Ariston water vertical water heater model ecovid 80ltr vr/3

Your issue will be on the input or mains supply side of your electrics.
Check your wiring for keakage to earth.

http://waterheatertimer.org/Water-heater-is-tripping-breaker.html

http://waterheatertimer.org/Figure-Volts-Amps-Watts-for-water-heater.html

http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html#new

Check watt rating and wire size
Gene

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

http://waterheatertimer.org/Water-heater-is-tripping-breaker.html

Gene

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Copy following link for troubleshoot walk-thru for electric water heater tripping breaker:
http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html#trip-breaker

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Sounds like you have a short in wiring for 120VAC system of water heater. Shut breaker at panel off, and remove cover on back of water heater to look for any burnt wiring at connections such as switch, or thermostat/eco assembly.

Electric water heater can be repaired by homeowner.

Four things can cause NO hot water:
1) ECO red reset button tripped. Remove top cover on water heater, push red reset button on thermostat. Put insulation and cover back over thermostat.
2) Circuit breaker is tripped, circuit breaker bad, or wire loose in breaker box. Turn breaker on-off and listen for crackling or fizzing sound, and burned smell. Test breaker for 220Volts. Test top two screws on upper thermostat to see if water heater has electricity.
3) Bad upper thermostat. Replace upper thermostat.
http://waterheatertimer.org/How-to-replace-thermostat-on-electric-water-heater.html
4) Bad upper element. Test upper element.
http://waterheatertimer.org/How-to-test-water-heater-element.html

If I understand correctly, you have electric water heater.
Heater suddenly stopped heating.

Four things cause sudden loss of water heater.
1) Reset button located under the top cover is tripped > turn off power, remove cover, press reset button > if reset keeps tripping, go to the troubleshooting link shown below.
2) Electric power to heater is interrupted > check circuit breaker > test for voltage > look for loose wire on breaker
3) Upper element burned out > test and replace element
4) Upper thermostat bad > replace upper thermostat

Reset button is best suspect.
Here is a link for complete troubleshoot and homeowner repair of electric water heater:
http://waterheatertimer.org/How-to-troubleshoot-electric-water-heater.html

Problem could be a shorted element. Disconnect the wires from the breaker and try to reset it, remember to flip the switch in the fully off position before moving it to the on position. If the breaker doesn't trip then the problem is in the heater itself. If you have access to an Ohmmeter, with the power turned off check the continuity of the elements across the screw terminals and from the terminals to ground. There should not be a reading to ground and a high resistance across the terminal screws

Tripping off at the water heater or at the breaker box?

I would say you have a bad element in the bottom.If the water is cold and heat until the top thermostat reach it tempture,then switch the bottom element and then the breaker trip.So replace the bottom element.