Ball Valve on Water Heater: Common Faults, Diagnosis and Repair 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...