You depend upon your hot water heater for showers and baths, dishwashing, laundry, cooking, etc. We take our hot water for granted most of the time, never giving it a second thought. That is, until it's suddenly not there. Or perhaps it's still there, but the supply has lessened considerably, or is taking longer to recover. Either way, you can't get by in that way for very long. The checklist below will help you discover the source of the problem.