A water heater may leak due to problems with a drain valve, condensation, excessive pressure or age. Some of these issues are resolved by making adjustments, while others require replacing the heater.
One of the most common causes of a water heater leak is a loose drain valve, which causes water to slowly leak out of the tank. A quick fix for this problem is to tighten the valve using a wrench. Home owners should be careful not to use too much force when tightening. Another common problem is condensation, when water naturally accumulates outside the tank. Condensation is caused when cold water enters the tank and the surrounding air is hot. It's easy to mistake condensation for a leak, but in reality, there's no leak. The excess water needs to be wiped off with a cloth.
Sometimes excess water pressure inside of the tank leads to a leak. When this happens it is likely due to the water temperature being turned up too high. The tank may also have a defective pressure relief valve, and the pressure is higher than the valve indicates. Adjusting the water pressure resolves this issue. Leaks are also due to the heater wearing out after a long period of time. Most water heaters last an average of eight to 12 years.