I have a park model RV (38 ft). The RV is permanently set on a site in an
RV park. (This is a weekend/vaca home) We have a permanent sewer hook up
from RV to sewer via flexible pipe.
Occasionally the toilet bowl will drain. It seems to drain slowly. It's
most noticable overnite or when we arrive for weekend stay.
There are no noticable leaks inside around the toilet or under trailer
around the pipe or connections.
Other than bowl draining toilet operates fine.
Could this be an issue with the plumbing vent stack being blocked ?
Any other thoughts or suggestions ?


Black Pyramid. Look down the hole with a flashlight and see what you can.
You will probably see a black pyramid. Most people think that when they
park a motor home that you just open the valves, and the poop runs straight
through. It does not. It drops onto the flat floor of the holding tank,
and the watery part flows off. Most of the exit pipes from a holding tank
are on the sides, not the bottoms, and some are an inch or more up from the
bottom. Over a time, this builds up an ever hardening black pyramid. To do
it properly, you must use it just like you do on the road. Empty it, close
the valves, fill it partially with water, use it, and when nearly full,
flush it out. Since you will not have the agitation that driving the MH
produces, you may have to assist this out of the tank. This can be done in
two ways. One is through the wall of the tank sprayers. Cost isn't bad,
installation not bad, but drilling new holes in holding tank might be. The
second is a simple PVC pipe with a cap on the end with holes drilled in it
to make a downward and outward sprayer. When flushing, put it in the open
top, and turn on water so that it flushes everything out. Put one of those
little 90 degree valves right where the hose joins the PVC, and you can
control it while watching it. I bought one that had a black pyramid, and it
took eight hours of flushing with the PVC wand at full force before the
pyramid broke up and went out the pipe.

This is a very common error among people who park MHs for a long period of
time. If this IS actually never ever going to move again, removal of the
holding tank, and installation of a continuous line would be the thing to
do. But who knows what will happen down the road, and selling the vehicle
without a holding tank may be a problem.

You say it has a permanent hookup. This might be true, but without the
total removal of a holding tank, the poop only goes as far as the holding
tank floor.

HTH

Steve