Peggie Hall writes:


Runback toward the toilet can be solved with a loop in the
line. Depending on how much you heel, preventing waste from
overflowing out the vent can be harder to do.

A loop would be difficult to install. The tank is installed relatively
high, with most of it over the waterline. Two reasons for that: one
because it fits nicely where it is (under the sink in the head), and
the second because it allows me to drain the tank by gravity: There is
a second outlet at the bottom which is connected to the original
thruhull. Of course, this is padlocked to make it legal within 3 miles
of the coast.

If I wanted to install a loop, it would either stick right into the
room over the sink, or I would have to butcher a nice nearby teak
cabinet really badly. Neither seems appealing. (OK, the idea of tank
contents seepage isn't exactly appealing, either...)


I have a Lavac toilet (with which I am so far extremely happy). Does
this make me more or less vulnerable to this kind of problem?

That depends on where the pump is mounted, but it should make you a
bit less vulnerable in any case.

Pump is very close to the tank, at the level of about the top of it.

But not to waste overflowing out the
vent. That can clean to a blocked vent line, so it's important that
you remember to backflush the vent every time you pumpout AND every
time you wash the boat.

Good ideas, but in THAT case I actually did follow your advice: the
vent fittings (yes, I DO have two of them, and they are led to the
bow, port and starboard) are sitting on the top of the tank, in the
centerline. So I should be safe with regard to that.

Although the outlet valve of the Henderson pump seemed pretty sturdy,
it is my only line of defence, right? Once liquid gets through the
pump, it can flow right out of the toilet.

INTO the toilet. A good reason to pay close attention to any needed
maintenance.


Well, that was kind of my point: If it can flow INTO the Lavac toilet,
it can flow OUT of it, right? (the tank is higher than the toilet)
There is no valve or anything in a Lavac that would hold it back.

And the only maintenance I can think of is to make sure the rubber
parts in the Henderson pump are OK, right?

This lack of necessary maintenance/rebuilding was one of the reasons I
picked the Lavac.

--Ernst