Lack of hot water pressure. Water going into the water heater tank has a very low volume or pressure, almost to a trickle. Discovered this by completely draining the tank, opened the supply valve and opening the drain valve. I can also hear that the water coming is of low volume. The 50 gl tank is only 5 years old. What caused this pressure problem. Cold water going into the house a good water pressure. Thank you. Florian

Could be a Clog in the cold water line before the water heater. Any Cold Water faucets before the water heater? If it works fine the blockage is between the 2.

I would suspect either the incoming shut of valve, or the nipple on the cold side of the tank. However, drain on water heaters can be decieving, as they tend to plug up very easily. So you may not be seeing the flow from the drain because its partially plugged. Try disconnecting the union on top of the heater on the cold side and see what kind of flow you have there. Let us know and we will do our best to help.