First off,if your builder hasn't solved it in 9 months he's either and idiot or you expect us to be wizards in solving it without benifit of even seeing the place much less troubleshooting the thing.
I wouldn't even pretend knowing which of several possibilities is responsible for introducing air but here's as good a way as any to minimize the effects. Install an air hammer chamber on discharge line of heater. Make certain it has both upper and lower drain cocks,

It could be gases created by chemical reaction between the anode in the water heater and chemicals in the water. Those substances in the water are not necessarily bad for humans. Interpretation of water tests is not my strong point. But I would suggest water tests to determine what may be in the water as a starting point.

This post was edited by bus_driver on Sun, Oct 5, 14 at 7:32

Chevy Man,you are on the cusp of appearing to be a prankster but giving the benifit of doubt,here's answers to the additional questions. As I said before,if the clowns working for you can't find source of air, how in he** could you expect us to????? Yes the spitting and murky color should be almost completly eleminated by the chamber. Yes,air is trapped at top each time tank is drained/flushed but it is bled off first time a facuet runs a few minutes. Visualize if you will how air ALLWAYS rises as bubbles in water. Air in a pipe with water will allways sit at top of pipe with water on bottom. In your case,the heater supply tees from topside of main supply. Air passing that junction will rise up the heater supply line while water continues on to the open cold facuet. No head scratching required,just a little common sense regarding physical science.
If it was gun to the head "take a guess or else" situation I would say new homes under construction is source of air. Meter taps,pressure testing,draining and refilling new plumbing over the course of construction and such. Send my compensation to the orphans widows and disabled firefighters fund.

Not a prank. We have an annoying problem. Builder wants to blame the Water District which has been out several times to check supply issues. Both neighbors on either side of my house (incidentally, both neighbors' homes were built by the same builder as mine), as well as everyone else on my street, has no issues. Can not find anybody in the community via Social Networking that has any issues like mine. Since I do not have issues on the cold water side and no one else has air in lines (cold & hot), I have ruled out a supply problem coming from the Water District.
From your description, I got a good visual regarding air movement in water lines. My builder did install hammer chambers in the walls at each hot & cold valve. I'm thinking, as you suggested, to install one on the top of the hot water heater on the discharge line of heater with an air bleed cock on top. However, I can purge the air by opening all hot water faucets anyway and by next morning, the air will be back and the problem persists.
If I pour from a hot water faucet a glass of the murky, milky water, the glass would dissipate the Dissolved Oxygen in about 15 to 20 minutes leaving my glass crystal clear. However, my pipes still bang and my hot water faucets still spit. I think the dissolve oxygen is being generated in my house somewhere on the hot side. My question is how does the air, Dissolved Oxygen, being generated in my hot water lines?
I am using the the Internet and plumbing forums in hopes that, maybe, someone else has had this issue like mine and found a remedy.
If my plumbing problem has never happened before, first time for everything. You can join us head scratcher.
As always, I appreciate everyone's help.
Thanks again.

Air will get in water heater or system when faucet will first turned on. Through this let the water will run the stops but returns if the hot water is not used for a while.

Here is a link that might be useful: septic tank covers

Hello Chevy-56, nice car btw. I experienced exactly same problem you
describe. I called the plumber, he walk in, immediately explained crud
in the tank emits gas. He drained the tank, flushed, and suggested a
flush every 6 months to a year. For me, we did not scratch heads.
Plumber knew his stuff, I am a happy customer. Hopefully, by now you
have resolved this issue, and I hope my detail will help others.

I have exactly the same problem. I have no idea how the air gets into my hot water lines . I recenlty installed a new hot water tank and its a simple one for one.I never had this problem before but now each morning I have nasty burps at the faucet I first use . Its great for the rest of the day but only in the morning do I get the trapped sputtering air. I do have an existing Vacuum relief valve attached to the cold intake line to the Hot water tank and itys probably 25 to 30 years old there is no leakage but could this somehow be allowing air into my hot water tank.? I am also scratching my head.

Abracadabra, HU see post #4 above for the source of your problem.

I have seen a few responses on other sites that it could be the chemical reaction of the Anode if thats what you refer to. The new Anode may be of a different material to the old tank. Thanks.

". I recenlty installed a new hot water tank and its a simple one for one.I never had this problem before but now each morning I have nasty burps at the faucet I first use ."

I was about to suggest you stop surfing looking for answers and have the installer earn his pay then I noticed you said . " I recenlty installed a new hot water tank ". If it was a diy job,the tank could have been overheated if lines were soldered. Was tank flushed to remove residues left from manufacturing?

yes klem I flushed the tank twice.

Its a Rheem with a magnesium anode.

I have the same exact problem and it started immediately after installing a new Rheem water heater. Any new update on your issue?

Yes I still get it occaisionally but not as bad now . I did not come up with a good solid reason. We do not have good water here and there are minerals and chemicals in it. But all my other tanks never had this problem . They may have had aluminum or zinc anodes I dont really know. I frequently cycle the hot water and keep on top of the problem. Good luck.

Yeah I have well water in central Ohio. It's not great water either, however we didn't have any issues with the last water heater. I'll change out the anode and see if that fixes it.

Swapped out the anode rod about a week ago now. Haven't had any air or sputtering in the hot water. The anode rod that I removed was pretty corroded. Looks like it fixed the problem for us! Hopefully this helps someone else that is having the same issue!