Having a noisy water heater is mostly annoying, but what is your water heater trying to tell you? As a water heater ages sediment accumulates on the bottom of the tank. The noise that the water heater makes when sediment has accumulated is often described as a rumble. This situation is not dangerous, but it is a sign that the water heater has lost much of it's efficiency. As the sediment builds up much of the heat is lost up the chimney and less heat in the water. A more direct effect would be the water heater overheating and the life of the tank being shortened. If your water heater is noisy, be proactive and call the experts at Charter Oak Mechanical. Charter Oak is the Manchester CT and Glastonbury CT water heater experts.   bbb