View Full Version : Shower has sewer gas when the water runs

Canuck of the Canorth
05-10-2005, 09:17 AM
OK, this may sound weird, but we have a second floor shower that has a trap, but it smells sewer gas when the water runs. Otherwise it is OK. The house was redone a few years ago before we bought it, with many screw ups, but I did manage to look under the floor and there is a trap, and it seems to have water in it, there is no odor normally. Just when we start the shower up, then it goes away.

The shower drains to a main stack/vent about six feet away, that goes up about 6 feet and out the roof. There is no separate vent on the drain. It doesn't seem to be evaporating, or being sucked out. I can smell the shower drain, see water below, then start the shower up and it smells for a about 30 seconds and goes away.

Any ideas?

05-10-2005, 02:42 PM
Six feet is beyond what code says, if I remember correctly, but wouldn't be the cause, I don't think. Could it just be from the water that was sitting in the pipes? Note, I'm not a pro...

05-10-2005, 04:17 PM
Turn on the cold water only and see if you have the odor. More than likely it is sulfur dioxide in the hot water causing the odor. Or, if you have a "marble" base, foul water could have accumulated under it and when you step into the shower to turn it on, the floor flexs and pumps the odorous water out.