A leaking pressure relief valve usually means getting a new valve. There is little that can be fixed on them, once they go bad.
Your leaking hot water heater may be from the pressure relief valve. The pressure relief valve is on the side of you hot water tank near the top. It may have a copper tube attached to it. This tube channels the hot water down to the floor.
When the pressure inside your hot water tank builds up to the danger level the pressure relief valve releases the pressure. This is safety feature that is built into every tank. When the valves go bad they start to vent when the pressure is not at the danger level. This can be just dripping to a full blown spray.
There is not an adjustment on a pressure relief valve. You will need to replace it if it is venting and leaking water. Go to the article 'Replacing a Water Heater Pressure Relief Valve' to find out what you need to do.
The 'Next' section discusses 'Leaking Hot Water Heater Pipes'. The 'Previous' section covers 'Leaking Water Heater Drain Valves'.