Plugged Drain

mommie53241 wrote:
This is whats under the furnace and coat closet left of stove You've got 2 pipes and 1 handle to the right of this is the sink and to the left in the shower. Hope this pic helps explain what I was trying to describe :)

Were not seeing the rest of the picture you are seeing, where these lines are going or from.

Is there another valve that is accessed from the little door shown earlier outside? Where do you connect drain/dump hose? Is the handle shown what you open to dump the tank (1 1/2" line?)
Not seeing any large lines normally associated with black tank.
edit: no black tank?

Dump valve inside? ...Wonder, just a passing thought, if valve shown is as diverter to keep replumbed lines from dumping into shower. If #1 goes to shower...The pipe that goes to left from valve..is that going outside or showere?
Wait a minute...

-Where does the pipe go from the valve at #1, (you said shower was to left, just verifying doesnt go out side)

-Where do the pipes go at #2, or are they just looped making a return just beyond picture, or is one going outside, the other up from something (sink or vent)

-The pipe at #3, Thats a large hole, is tank behind that?
If not tank then drain from kitchen?
-The angled pipe at #4, any idea where that goes (i guess vent also)

Ya know Ive been assuming 2 tanks-looking at this picture with no other info only one tank (IF it even has a tank)?, some one replaced, or at least replumbed, for what ever reason lack of correct fall the kitchen line will flow into shower if valve open, Im assuming valve is inbetween shower and one of the lines at #2 lead outside. Sure would like to see exterior valve and how you dump.
More than likley Im 180° off