If you’ve ever been in the shower when the hot water runs out, you know first-hand how frustrating water heater issues can be. These conditions can point to different problems, but the most common one is a failed heating element. Watch the hot water faucet you left open—when water flows steadily from it, the tank is full. The last thing to do is to flip the water heater breaker back on, wait a couple hours, and test the hot water. Last thing to do is flip the breaker back on, wait a couple hours, and check to see that you’ve got hot water again.