That “popcorn” noise drove me nuts for a while too. Flushing didn’t do much except make the water look like weak coffee, and I’m pretty sure my dog still hasn’t forgiven me for the racket. I’ve heard about the vinegar trick, but honestly, I’m not wild about pouring gallons of it in there. Replacing the anode rod helped a bit with smell, but not the noise. At this point, I just cross my fingers and hope the tank holds out until I can justify a new one...
I get being hesitant about the vinegar thing—dumping a bunch in the tank just feels weird. But honestly, flushing should’ve helped more than it did. If you’re still hearing that popcorn sound, it’s probably a thick layer of sediment baked onto the bottom. Sometimes, the drain valve gets clogged and you don’t actually get much out when you flush. I had to poke a wire up into mine to break up the gunk before anything came out. Not saying it’s fun, but it made a big difference for me. If you haven’t tried that, might be worth a shot before giving up on the old tank.
I get where you’re coming from with poking the drain valve, but I’d be careful with that—sometimes you can damage the valve or push sediment further in. Have you checked if your anode rod’s shot? I’ve seen tanks make all sorts of weird noises when the rod’s gone and the sediment just keeps building up. Sometimes it’s less about what comes out the drain and more about what’s stuck inside. Just a thought...
I’ve seen folks get a little too enthusiastic with poking or flushing and end up with a leaky valve, so yeah, careful’s the way to go. But I’m curious—have you actually drained the tank recently, or just tried to poke the valve? Sometimes that “popcorn” noise is steam bubbles forcing their way through thick sediment layers at the bottom. If the tank hasn’t been flushed in a while, it can get pretty caked in there.
You mentioned the anode rod—good call. When those are gone, tanks start rusting inside and all sorts of weird stuff can happen. Ever pulled one out and found it’s just a wire left? Wild how fast they can disappear depending on your water.
Another thing—what kind of water heater do you have? Gas units tend to make more noise with sediment buildup than electric ones, at least in my experience. I’ve even seen some where the dip tube was cracked and cold water was dumping right onto the bottom, stirring up even more sediment.
Ever noticed if your hot water looks cloudy or smells off? Sometimes that goes hand-in-hand with these noises and points to bigger issues inside.
Just thinking out loud—have you tried feeling around the base for warmth or leaks while it’s making those sounds? Sometimes you can catch a small leak before it gets out of hand...
Had a customer once who thought the “popcorn” sound meant the heater was about to blow. Turned out it was just a mountain of sediment. Flushed it out and the noise vanished. If you haven’t drained it in a while, that’s probably your culprit. Sometimes those anode rods are gone way faster than you’d think, too—especially with hard water. Never hurts to check for leaks around the base while you’re at it... caught a pinhole leak that way last month.