A leaking hot water heater can cause severe damage to your home. This is why a quick repair is needed when water is found near the hot water system. There are a few reasons that hot water tanks develop leaks. 

1. Internal Corrosion

Water tanks are typically made of two material layers with insulation between them. Any rust or damage on the exterior layer is easy to see, so it's the corrosion that can form on the inside that is the greater risk. Leaks from internal corrosion tend to appear near the bottom of the tank. The corrosion can be the result of age or hard water buildup in the tank.

2. Drain Valve Damage

The drain valve is located near the bottom of the hot water tank. Its purpose is to drain water from the tank in the event repairs or needed or during periodic maintenance flushing. Sometimes a leak here just means the valve isn't closed completely, so it's an easy fix. In other cases, the seals in the valve could be wearing out, which means they will need to be replaced promptly. 

3. Pressure Issues

Every hot water heater has a pressure relief valve or tank that is designed to prevent the tank from bursting in the event of pressure buildup. Pressure can build up due to sedimentation, an overheating thermostat, or problems with the pressure relief system. If the issue is with the relief system, the leak will be at the top. Any other cause can lead to leaks from any fitting or valve location, although those near the top of the tank are usually affected first.

4. Hose Bibs

The hose bibs connect the cold water inlet line and the hot water outlet line to the tank. Over time the fittings can wear out, causing a small leak. If this leak isn't repaired right away, the connection will continue to wear until it gives out completely. This can result in a major leak. Use extreme caution if the leak is from the hot water outlet, as burns could be a risk. 

5. Sedimentation Buildup

Sediment comes from minerals in hard water that precipitate when the water is heated in the tank. In a newer tank, there are anode rods that attract the sediment so it doesn't cause problems. In older tanks or in areas with very hard water, the tank must be flushed periodically to clear excess sediment. Otherwise, the sedimentation can restrict water lines and cause corrosion, both issues that will lead to leaks. 

Contact a water heater repair service if you notice a leak in or around your hot water heater.