Why Does My Water Heater Make Popping or Rumbling Sounds?

Popping, rumbling, or banging sounds from a water heater are caused by sediment buildup on the bottom of the tank. As the burner heats water trapped under the sediment layer, it creates steam bubbles that pop through the sediment — producing the noise. Annual flushing removes sediment and eliminates the noise. If the sounds are severe, the tank may be near the end of its life. Hard water (very common in Southern Maryland) accelerates sediment buildup significantly.