There was a homeowner who had a low wattage water heater which worked fine on a 240V 15 amp breaker. Then one day a heating element went out...
The homeowner replaced the heating element, except purchased a higher wattage heating element (wrong element). Then when the heating element was installed the breaker kept tripping.
So the homeowner purchased a new water heater and this new water heater was a higher wattage then the old water heater. The breaker again kept tripping.
Then the homeowner replaced the circuit breaker with a new 15 amp (double throw) breaker. Same problem. Homeowner kept turning on the breaker to try to get the water heater to work...
Then with the wires to the water heater disconnected and the breaker turned on, there was no voltage to the wires. Seems the wiring was "fried"!
In the end the homeowner had to pay for an electrician to install new higher amperage wiring and a higher amperage breaker, plus had the cost of the new heating element, the new water heater, and the new 15 amp circuit breaker.
All of this could of been avoided if the homeowner had replaced the heating element with the correct wattage element!