In my new house (6 months old), the vent pipe is extended into the sump pump pit. When the heating season started, in October in MI, we experienced a sewer gas smell coming from the vent pipe. Our plumbing contractor put silicone caulk around the cover of the sump pit and the pipes coming out to no avail, the sewer gas still leaked into the basement. My questions are:
1. What would be wrong with removing the vent pipe from the sump and sealing it and running a fresh air vent into the sump to provide the neccessary air pressure to make the pump work? Only the furnace (hi-efficiency) and floor drain go into the sump.
2. Why isn't the sewer gas rising out the vent pipe in the roof?

 

I'm confused -- WHAT vent pipe is extended into your sump pump?? And what does the sump have to do with sewer gas?? You can't dump the outlet of a sump pump into a waste or drain system, and you can't dump a waste or drain line into a sump pump.

 

This is the second house I have occupied in
Michigan, where the floor drains in the basement go into a sump pit that is then pumped thru a valve into the waste system. It is a common practice in Michigan as far as I know. What would be a good reference book for correct practice?

 

I think we have a terminology problem. What you're calling a sump pump pit, I would call a sewage ejector basin. What I call a sump pump pit handles ground water only, not anything that goes through a floor drain or is connected to a sanitary sewer.

 

OK, whatever, but remember in your advice on how to fix it, there isn't any sewage in there, just water.