Sewer Gas -- but no water leaks ????????

[MechanizedMan]

Hello,
For the last few days, each time the commode is flushed, the odor of sewer gas becomes almost overwhelming. I had this problem a couple of years ago, and replaced the wax seal but it was leaking water onto the floor also. However, this time there is not any evidence of the commode leaking. I went up on the roof and checked the vent stack, but it appeared to be unobstructed. Is it possible for the wax seal to leak gas but not water ???? I have a fair layman's knowledge of plumbing, simple systems anyway, and this one is about as simple as it gets. The tub, lavatory and commode are all on the same wall and each one drops into a 4" cast iron line, with a 4" cast iron vent stack. I will also add that there are no problems with the tub/lavatory draining, or with the commode flushing. Everything works perfectly. What gives ????? Any help greatly appreciated.

Thanks,
John

[HayZee518]

just for ha-ha's try two wax seals. could be the toilet to flange distance is too great! normally the flange should sit slightly above the finish floor with the closet bolts bringing everything tightly together. as far as the rest of the fixtures, each has it's own trap to isolate the sewer gas as each device is used.

[MechanizedMan]

Thanks for the reply Hayzee. The flange is on top of the finish floor, so I don't think that's the problem. Is it fair to say that this is the only possible cause, in this particular case ?

[HayZee518]

if you don't mind the $2.50 expense try another wax ring and see if the problem still remains.

[MechanizedMan]

Thanks Hayzee. Don't mind the expense, just want to be sure I'm solving the problem. But, I have some new info which is that the odor is only present in the early mornings, you don't notice it during the day or evening. Could there be a back up in the city sewer line ? If there was, seems like it would be present all the time until the clog was cleared. They do have the vacuum truck down at the end of the street every time you look, it seems like. Well, anyhow, I'll go ahead and change the wax ring, per your reccomendation. I'm just a stickler for finding the "smoking gun" (no doubt one of my many downfalls in life). Thanks for taking the time to reply and I'll post back the results. Thanks again.

[HayZee518]

the waste line going out from your house to the street normally should have a quarter inch pitch per foot but I've never seen a town crew install anything by code. they figure as long as the home run pitches the pipe away from the dwelling they're within the scope of the code. a wad of effluent would probably take a few days to make it to the street drain to say the least.