Inspect your fittings. Don’t know which fittings you need to inspect? Check all of the following; make sure the fittings are tight and dry. Use a cotton swap or Q-tip to wipe around the areas to make sure they are free of moisture and rust.
First look at the hot and cold water lines. You’ll find the pipes on top of the water heater; the cold line is always the right pipe and the hot line is always the left one. Make sure the pipes are free of rust. Also check the ball valves on the hot and cold lines; the nut used to rotate the lever can loosen enough to cause a leak.
Next, inspect the T&P (Temperature&Pressure) valve. This will be on top of the water heater for some electric water heaters, but for all other water heaters the T&P valve will be attached to the side of the water heater. It looks like a spout with a 1 inch long movable lever. In some cases a piece of plastic pipe is connected to the spout.
Next, check the drain valve at the bottom of the water heater. It looks like a standard outdoor hose bib.
Lastly, on electric water heaters, check the thermostat (behind a panel on the upper half of the water heater) and the lower heating element (behind a panel on the lower half of the water heater).
If any of these areas show signs of leakage or rusting, wrap the fitting with Teflon tape if possible. Call a plumber for maintenance on any of these areas.
Fix the leaky fittings. Remember that if any of the areas discussed begin leaking, especially the hot and cold lines and the ball valves on the lines on top of the water heater, water and rust can cause serious damage to the tank itself. Leaks can in time destroy the water heater, requiring a brand new water heater to replace it. If you notice water stains on or around the water heater, the valves and lines above the water heater to see water is leaking all over the water heater. Call a plumber immediately.
Some advice about insulation. If you’ve followed some energy conservation advice – such as installing an insulation blanket or insulating the pipes – be aware that any leaky fitting will be hidden beneath the insulation. Also insulation blankets can cause rust to appear faster underneath it than if there was no insulation. Never insulate directly around fittings, especially the hot and cold water lines and the T&P valve.
Types of drain valves to install. The drain valve is located at the bottom of your water heater. There are a lot of water heaters that come equipped with a plastic cone-shaped drain valve. These cause problems frequently, due to their easily breakable nature. If you already have a faucet-type drain valve with a knob, then you're probably okay with that because these drain valves are extremely durable. If you have the cone-shaped drain valve, consider having a brass hose bibb installed instead -- or better yet, a brass ball valve. The brass ball valve allows for the easiest flushing of the water heater and is the best of all choices.
Not all hot and cold lines have ball valves of any kind. It's not critical if you don't have them, but consider having them installed.