Blackwater valve pulss open but nothing drains out.

GENECOP wrote:
Often the cutout from the drilling of the tank gets left behind and causes a clog....if the handle feels the same....resistance etc...it probably a clog....if you do not have one it's time for a flush kit...get the kind that attaches to your drain, it clear, and has a hose connection that will let you shoot water up the drain.....good luck...