Head and Holding Problems

[Mark Mickelson]

Lately I've been having trouble with the holding tank flowing back into the head as though the tank was over-full. Also, we get quite an aroma when the head is pumped, coming from around the dodger. The pumping service says they aren't getting much and I tried it too at the dock station with little coming out. After much torture, I got the vent hose off the hull fitting and found the airway was not obstructed in the vent hose to the tank. Could it be the hull fitting is blocked for the 1/2 inch or so long it is? The macerator now makes a small noise, where it used to make a big noise, and it doesn't seem to pump anything anymore (emergency procedure only). Any experience or suggestions out there would be appreciated.

 

[Tim Schaaf]

some thoughts

You might try spraying your hose nozzle into the vent to dislodge whatever might be in there. The back flow into the toilet can also result from a Joker valve which needs replacement, or a dirty one that doesn't seal completely. Put a quart of white vinegar in the head, add a like amount of water, and pump half of it through. After awhile, pump some more. Repeat until all the vinegar has passed through. At some point you should probably let the whole thing sit overnight. This process will clean the Joker valve and the hoses. Next, squirt a few teaspoons of baby oil into the head, fill it about half-way with warm water, then pump the whole thing out. The oil lubricates the various parts. If you still get the backflow, consider repeating with muriatic acid (be careful, the stuff burns) or replacing your valves. But see if the vent is clogged before you do anything else!

 

[Peggie Hall/Head Mistress]

Check the thru-hull!

Everything in your description of your problem points to a blocked tank vent that's pressurized your tank, and the thru-hull is the most LIKELY place for a blockage to occur, especially if it's the type that has a slit covered with a screen. The screen rusts...becomes a trap for dust, dirt, pollen etc. So knock the screen out if there is one. Even if it's not that type, insects--especially dirt daubers--love to build nests in through-hulls. And if you ever overflow the tank, the thru-hull is where bits of waste are most likely to become trapped. Checking all through-hulls for blockages should become as much of a routine as washing the boat (in some cases MORE of a routine!) Each time you pump out, back flush the vent with water to clear out anything that's overflowed into it due to heeling. And I also think you might profit from reading the articles in the Head Mistress forum Reference Library (on the forum home page).