First try tightening the valve to see if that stops the leaking.
Cold water inlet valve water heater.
I doubt it is welded to the tank but there should be one somewhere around the water heater inlet or outlet to help balance the cold and hot water system.
The cold water inlet valve allows the flow of cold water into the heater.
So check for any leakage or damage to the ball valve.
For more information see water heater leaking from the top.
If it doesn t the valve most likely needs to be replaced.
If the valve itself which sits higher up on the pipe has gone bad it will drip water down the pipe and onto the top of your water heater.
Attach the blue coded fitting to the cold water inlet with the arrow facing into the water heater.
All are easily fixed.
The hot water outlet pipe also has a valve that will shut down all hot water leaving the water heater.
Your cold water inlet valve is where cold incoming water from your home s main water line enters your water heater.
A cold water inlet valve often identified by a blue handle feeds cold water from the main supply into the water heater.
This is the valve to shut off if you need to repair or replace the water heater.
You need to look for a ball valve or gate valve which will allow you to turn off the water.
If you believe you have a leak near the top of your electric water heater it could be one of a few things.
The cold inlet or hot outlet pipes may be loose the t p valve may have failed or inlet valve may be leaking.
Both have arrows showing the correct direction for installation.
Attach the red fitting to the hot water outlet with the arrow pointing away from the water heater.
If the valve that delivers cold water to your tank has gone bad it will drip water onto your tank.
This ball valve is responsible for cold water inlet to the pipe.
Frequently the cold water inlet valve sits directly above the heater.
So the first thing that you need to do is to check the cold water inlet pipe.
Turning it off will stop the water from entering the tank when you need to carry out maintenance repairs or to drain the tank in preparation for a replacement.
You can attempt to replace the valve yourself following these instructionsor have a professional replace the valve.