Hi ho!

My son bought a house with an overhead sewer system.

It looks like the basment back-discharge toilet was added in recent history. There is also a utility sink with its own motorized pump connected to the sewer drain discharge pipe (on its way to the street). The main sewer system has a "pit" where the basement toilet connects and the main drain is pumped to the street.

He has a floor drain in an adjoining room that smells upon occasion. His theory is that the drain trap has the water siphoned out of it when the basement (only) toilet is flushed.

I have avoided overhead sewer and/or sump pump properties in my lifetime. Now, alas, I am interested in learning about the dynamics of an overhead sewer system.

Tried the library and internet but have had virtually no success in seeing a diagram or explanation of how overhead sewer systems work. Can you refer me to an authoritative source.

It would be real interesting if we knew how the pipes (PVC) were run or who did the work. Talked about having a plumber or Mechanical Engineer that does HVAC stuff come in 'splain things, but it seems like we should educate ourselves if and before we bring in an expert.

One suspicous thing he found is the vent from the basement bathroom running to the attic where it crossed over and runs back down to the "pit" vent without tapping into an outside vented soil stack.

Thanks for reviewing this and any advice or referral will be appreciated.

Regards,
Budmann

Hi Bud, Welcome back,  Hope your shower drain is working OK.  I'll discuss Grinder pump systems later but first let me get rid of your sons stinky floor drain.  The numnuts that put your basement plumbing in left you unvented.  He might have thought he was tying back to a revent but what he did was to tie to another vent leaving them both unvented.  Bad news!  Sewer gas is both poisonous and explosive.  When the trap seal is pulled out of the floor drain it lets sewer gas escape.  To remedy this cut a drainage tee into the cross between the two vents.  Point the branch towards the outside vent.  Now run horizontal  to another drainage tee,(that you will cut into the vent stack,) turned upside down on the outside vent. Figure the height of the upside down tee at 1/8 times the footage of the horizontal run and that will  give your horizontal run 1/8" raise to the foot from the crossover tee to the vent stack tee.  NOW, you're vented.  Bud, were you thinking of changing over to a grinder pump and a holding tank?   Why?  You have the better system now.   Cheers,  Tom