Sounds suspicious that the gas valve that worked fine with the old board now chatters. Or it could just be you are paying more attention and noticed an existing problem. I would try to get a voltage reading on the gas valve. Should be close to what ever rated, usually 24 volts AC. If OK, it may be going bad. If not, you need to talk to whoever you bought the board from. If they insist it is the gas valve, see if you can make a deal, your buy a new gas valve, and if that doesn't fix the problem, they take both back. Perhaps before that, try wiggling the plugs around a little to makes sure they are all seated good.