jhalat Report post Posted March 11, 2012 I have an Atwood 10 gal water heater that has started making a humming noise whenever I turn on any hot water faucet. I'm hooked up to city water with a regulator in line. The humming noise is not coming from the faucets, but the hot water tank. Share this post Link to post Share on other sites
wolfe10 Report post Posted March 11, 2012 Wonder if you have a check valve that has mineral deposits on it? If you can access the back (inside) of the water heater, see if you can more closely identify the source of the sound. Share this post Link to post Share on other sites
jhalat Report post Posted March 11, 2012 Vibratiion seems to be coming from the top valve. Not sure what valve it is. Share this post Link to post Share on other sites
wolfe10 Report post Posted March 11, 2012 Top valve when opening the outside access door or top valve in the inside/back? The top valve accessed from the outside is the: Pressure and Temperature (P&T) Relief Valve. Share this post Link to post Share on other sites
jhalat Report post Posted March 11, 2012 Top valve on the inside access panel, the back of the tank. I've tried to find what valve this is on the internet, but no luck. Share this post Link to post Share on other sites
wolfe10 Report post Posted March 11, 2012 Top valve on the inside access panel, the back of the tank. I've tried to find what valve this is on the internet, but no luck. Suspect it is just an in-line check valve. It keeps water you heat up from flowing into the cold water part of your system if on the cold side. If on the hot water outlet side, it prevents water from flowing back into the water heater when the water heater is bypassed for winterization on some coaches. Share this post Link to post Share on other sites
jhalat Report post Posted March 11, 2012 Thanks Wolfe10, now I know what I'm looking at. Share this post Link to post Share on other sites
hermanmullins Report post Posted March 12, 2012 It is very important if you can identify the tune. Is it Current or and Oldie? As Brett said it sound like calcium build up. If you can see the valve tap on it every so lightly. You may be able to dislodge it. Also, you might try blowing out the water line just like you would to winterize it. This also might dislodge the build up. Share this post Link to post Share on other sites
vtbigdog Report post Posted March 12, 2012 How is your hot water pressure compared to the cold water pressure at your sink faucet? Do you have a bypass valve? If you do, go to your sink and turn the hot water on full blast. Then throw the bypass handle back and forth several times which will cause the check valve to fully open and close rapidly. This may free up the valve. Share this post Link to post Share on other sites
