Hot water heater not making hot water. Diagnose and find leaking gas control valve. 20 year old Bradford White water heater. Recommend replacement Rheem tank water heater, or Navien tankless water heater. Average water heater life span is 8-12 years old. Install new Navien tankless water heater with new pan and test for functionality. Recommend water leak protection device (FloodStop) to prevent future damage from water leaks.