Atwood GC6AA-10E

[mgmgmg75]

Last year when winterizing, I had to remove and plug the top line coming off of the water heater to keep the anti freeze from running out of the hot water tank. Starting the new year I have a buzz, vibration noise in the water system. Seems to be coming from what I believe is a check valve. Can someone confirm before I tear into it. Is this a generic check valve?

[Old-Biscuit]

YES it is the check valve in HOT Out port
Vibrating/buzz noise from failed check valve....O-ring dislodged....plunger cockeyed----reason antifreeze backflowed

RV MFGs install them cause they are cheap and little labor

Standard 1/2" NPT check valve
*If you have room/easy access install a shutoff valve instead of new check valve and just install a nipple