Have you gone down to into your basement and you've heard the water heater rumbling? Like, turned on, it sounds like there's rocks in the bottom of the water heater? Like it's really churning? When I get asked what that means, what it is that the sediment in the bottom of the tank, a lot of it, as the heat gets it warm, it's really just kind of boiling the sediment and the sediment's breaking free and kind of flaking down below in the lowest part of the tank.
When you hear a noise like that, it's all related to sediment. And it's all related to the heat burning through it. There's nothing potentially wrong with the water heater, but the sediment can potentially be detrimental to the life of the water heater. It can cause it to leak prematurely.