Jamming or sticking is another problem that can affect the ball valve on a water heater. This can happen when there is debris or sediment in the water that accumulates inside the valve. For instance, in areas with hard water, minerals can build up inside the ball valve on a water heater and prevent it from turning smoothly. To diagnose jamming in the ball valve on a water heater, try to turn the valve handle. If it is difficult to turn or feels rough, it is likely jammed. You can also disassemble the valve carefully to check for any visible debris or sediment. To repair a jammed ball valve on a water heater, cleaning the valve thoroughly is necessary. Use a brush or a small tool to remove the debris and sediment. In some cases, lubricating the valve parts can also help it to turn more freely.