What do I do about a hot water heater that has a slow drip from the overflow valve? The heater is just over 10 years old and we live in area with lots of lime in the water.

If you have a sprinkler system or backflow preventer then you should install a expansion tank. If not then work the lever up and down to clear the seeat. If that don't get it shut the power and water off and replace theT & P Valve. Good luck, tom