Holding Tank Clog

[zman18]

When I went to dump my holding tank through the bottom valve it did not dump. It pumps out fine using a pump out facility but doesn't dump using gravity. I'm assuming there must be a clog at the bottom. Anyone else had this problem and/or suggestions on the least messy way to fix it?
Thanks

[TBOT422]

You may want to check and make sure the vent is not clogged. Does it gravity empty if you take the deck cap off? The tank will not gravity drain if it can not get air in the tank.

When pumping out, you should fill with fresh water and pump out again several times to hopefully break up any bottom clogs.

You might want to also want to check this thread which describes a holding tank flushing 'gizmo' on the Head Forum. http://www.catalina350.net/phpBB3/viewt ... izmo#p2922

Good Luck

[jonnjones]

This happened to me once. If found a clog at the outlet - plugged with marine growth. To fix it, I pushed a coated wire (a la coat hanger) into the hole and bingo - out came the contents. I'd do this some where secluded, though, as there is sure to be some effluent once you clear the clog.