Bang or Ping in water heater

I looked at some old threads and I'm not sure if I'm on the right track. I get a "bang" in the water heater, one only, as it nears its heating cycle, when I turn a valve off (like the sink or shower), or sometimes while it's just sitting there doing what water heaters do. It's an envirotech water heater and only 4 years old. Super hard water that leaves stains on glass and vehicles I can't remove. I've flushed several times. Installed a H20 pressure regulator, I have an arrestor on the hot line below tank and cold line by the outlet to sprinkler system. Anyone had anything similar? Is it the tank and buildup? Any ideas? I'm thinking of replacing tank next, but eliminating by removing appliances is expensive!

Are we talking a natural gas water heater?

Type of water heater

It's a propane monster.

w/h noise

You will get a better explaination from someone, but the bottom of the water heater is like the bottom of a tea kettle and the elements that are in the water settle out to the bottom. Some of the oxygen or air gets trapped and will pop when water begins to heat. Some heaters sound like a popcorn popper.

Get a Softener

You will probably have short life on water heaters until you install a water softener, based on a water test.

The problem arises from the fact that calcium carbonate precipitates when the water gets hot. That is why teakettles get thick crusts in the bottom.

The cause of the popping is steam bubbles that are created where the flame heats the metal that is somewhat insulated on the inside by the deposits. The creation and collapse of those steam bubbles is what makes the noise.

Just as you can clean your teakettle by boiling a little vinegar in it, you could clean a water heater by circulating a muriatic acid solution through it. That is a solution that many homeowners might not want to undertake.

You could circulate the acid solution using a "drill pump", or better yet, a small centrifugal utility pump.

I would live with it or replace it.

banging in heater

it is probably what everyone else has alaready stated...


I have run into where the baffle going up the chimmney
expands and contracts when it ti heated and makes a
slight banging noise too. try spinnning the baffel in the
chimmney and see if it helps...

Water heater bang

Guess it just sounded so unusual because it sometimes happens when you shut down a cold water line. Makes no sense.