Water Heaters - noise from hot water heater

ok so i've heard this noise for quiet some time. At first i thought it was my neighbors.. but its not. It seemed to go away during the winter, but now that summer is in full swing i hear it constantly. The last couple nights the noise has been constant, and even woke my girlfriend up multiple times.

The only way i could get it to stop was to run a faucet... I didnt have to run it a lot, but a tiny stream would make the noise go away.

I've flushed the water heater, and also hit the valve on top (part number 5) for a little bit, and the noise seems to stop for a couple hours.

The noise sounds like someone is hitting the copper pipe with their knuckle, at a pretty firm rate. ;)

I've labled the below pic of my setup. I have some questions already, like why there are so many valves, and I'm curious as to what part number "4" is. Pressure valve maybe?

I'm looking for input on how to make the noise stop. Closing valve "1" all the way makes the noise stop too...

http://farm4.static.flickr.com/3191/2581648825_5fd7b79b21_b.jpg

donbondave,

Valve #3 is your cold water input shut off. #5 is the T&P valve. Valves #1, #2 and #4 seem to be connected only to the cold side of your plumbing, and #4 APPEARS to be a PRV. (Kinda hard to tell from that picture -- there's a pipe in the way!)

Your problem sounds as though the incoming pressure is too high. Put a pressure guage on a cold hose bibb, and if the cold pressure is more than about 50 PSI, adjust valve #4 (If indeed that's what it is!) so that your incoming pressure is about 50 PSI.

hey lefty. By cold hose bib do you mean... like the garden hose outside? Thats about the only thing i got... The thing with that is that I don't think the #4 the PRV gets used before the hose outside. My home is a condo by the way...

Can i give the PRV a turn or two? Maybe 1 turn clockwise? Or a quarter turn? It has a notch for a flathead...

Check this out


http://www.bradfordwhite.com/trouble_electric.asp#rpwh

yea that doesn't really help me too much, I'm going to give the PVR a turn and see how she sounds...