Suspicious Noise Question

[broken line]

Recently we installed a new water heater - since then, I am hearing noises (hard to describe) that sound similar to metal hitting or clanking on metal. I cannot find the source of this irritating sound, and initially thought maybe it was the heat ducts expanding when the furnace turned on but I'm not sure.

Can cutting and re-installing the water pipes change something (air in lines, water pressure, etc) that would cause the pipes to make noise.

I promise I'm not crazy here but the noise is getting old.

Any suggestions much appreciated.

[eyebjim]

Air bubbles in water lines can make the pipes shake causing them to hit eachother and make a clanking sound. See if you can find any pipse close enough that they could hit and cover them with some foam tubing. Just a thought.

[sticknstring]

Could be the water lines, but usually immediately following turning on the water and having the lines fill up again.

I'd bet on the heating ducts expanding when the furnace kicks in. Ours will do that on occasion as well.

[Whoaru99]

Was the plumbing, by chance, altered in such a way that something resembing an upside down "U" has been created in the pipes? If so, it could be air getting trapped in that portion of the pipes and may be difficult to get it bled out as any air will keep accumulating there.

[Macgyver55]

Turning on hot water can sometimes result in creaks from the expansion and contraction of the pipes themselves in the holding brackets. Possibly changing the length of the pipe when installing the water heater aggrevated it at some point.

[CAMAN]

Is it gas fired? If so, inside the flue that goes up the middle of the tank is usually a steel fin that hangs from the top and diverts the heat toward the tank. If it isn't hanging properly or the tank is balanced on something and rocks back and forth slightly it will make a noise that you described.

Remove the top flue and check to make sure it's installed correctly. If it is and it still makes noise try and pull it up and put a slight bend in it to allow it to wedge itself slightly against the side.

[TurnUpTheFishing]

Maybe water hammer? Caused by air pockets in your water pipes.

When does it make the noise? randomly?