When an electric water heater fails to heat water, either the power to the water heater may have been interrupted or there is a problem with the controls or heating elements. Perform these diagnostics:

1) Be sure electricity is being delivered to the appliance. Check the main switch on the water heater and the circuit breaker (or fuse) that serves the water heater. If the circuit breaker has tripped, reset it by flipping it all of the way to "Off" and then back to "On."

If a fuse has blown, replace it with a new fuse that has the same rating. If the circuit breaker or fuse repeatedly blow out, call a qualified local electrician to check and repair the circuit. Note that the water heater should not share a circuit with another appliance--it draws too much power when heating.

2) Check the high-temperature cutoff in the water heater. Open the panel and push the reset button. If the button doesn’t make a clicking sound or you still don’t have power after pressing it, then your high-temperature cutoff is probably bad. Call an electric water heater repairperson.

3) If there is any water inside the compartment, this could cause the thermostat to malfunction. Leaking water means that your water heater may need to be replaced. If this is the case, be sure to see the HomeTips Water Heater Buying Guide.

If these steps don’t solve the problem, you may have a problem with your heating elements. You can replace these yourself following the manufacturer’s instructions if you feel comfortable with this level of repair or call a water heater service professional.