popping noise - not sediment?

[bradc2009]

My water heater is not quite 5 years old and has been making popping noises, particularly after someone takes a shower or we use hot water to wash the dishes. I know that's supposed to be evidence of sediment build-up, but when my father-in-law helped me flush it, the water came out clear. He only allowed a small amount of water to come out, but he said the sediment should have come out right away, so he assumed there wasn't any, since it was clear.

Could something else be the culprit? Or should I drain the tank completely?

I read elsewhere that sometimes sediment won't come out, if the chunks are too large. If that's the problem, is there a way to break them up and get them out?

We have never flushed this water heater before. We have hard water, so it seems like we probably would have sediment build-up.

Thanks.

- Brad

[SewerRatz]

• You will need to turn off the gas/ electricity to the water heater along with the water supply.
• Drain the tank all the way down, and then carefully remove the drain cock.
• I normally install a 3" long ¾" nipple in its place with a full port threaded ball valve to help add in this process.
• Now that the ball valve is in place I take a stiff wire, like a coat hanger and poke and scrape along the bottom of the tank to break up the sediment.
• Then I turn the water supply on to the tank to help flush the sediment that I loosened up out of the tank.
• Rinse and repeat till you no longer get anything coming out anymore.
• Remove ball valve and nipple and reinstall drain cock. If old drain cock is plastic then leave the ball valve.

[bradc2009]

Thanks for the quick response. Is the drain cock the spigot that I attach the hose to for draining the tank?

And what is a ball valve?

[SewerRatz]

Yes the drain cock is the part you hook up the garden hose. Here is a picture, they claim it is worth a 1000 words.

[bradc2009]

I'd say that picture is worth a million words!

Many thanks for the info. Very helpful.

[bradc2009]

One more question: My drain valve comes off a pipe that's attached to my recirc pump. Do I need to turn anything off on the recirc pump while doing any of this? There are handles below and above the recirc pump that can be turned to an off position. The handles look like the red handle in your photo.

[kingsotall]

Unplug the pump.
btw, that is a dandy pic Ron!

[hj]

Most of the popping is caused by rust/mineral nodules which build up on the center flue. They are basically a closed bubble so when the water inside them is heated by the flue gases they become superheated steam, which then is blown into the water in the tank. When it condenses it does so with a "mini explosion" which is the popping sound you hear. They are bonded to the metal so they do not flush out. When the "hole" gets large enough so the water can circulate while being heated, the noise will cease because the superheated steam cannot develop.

[bradc2009]

So, there's nothing I can do about the sound? Or should I still follow the steps recommended above? Thanks.

Most of the popping is caused by rust/mineral nodules which build up on the center flue. They are basically a closed bubble so when the water inside them is heated by the flue gases they become superheated steam, which then is blown into the water in the tank. When it condenses it does so with a "mini explosion" which is the popping sound you hear. They are bonded to the metal so they do not flush out. When the "hole" gets large enough so the water can circulate while being heated, the noise will cease because the superheated steam cannot develop.

[hj]

No, but have hope, because it should go away when the steam eventually wears the nodules away, or alters them so the condition does not occur. Mine did it for about a year and now it is quiet again. Another condition that can cause the noise is opening a faucet while the heater is running. That reduces the pressure in the tank so the water in the nodules becomes superheated instantly and thus causes the noise sooner that normal.