Hello, we are building a new bathroom and have left the toilet pipe and the shower pipe open. We have noticed that water from the front bathroom is now draining and coming out of the open toilet pipe (no toilet installed yet). My question is, is this normal or do I have a blockage in another part of the draining system? Is the open pipe act as a vent of sorts and the waste water is actually flowing to the back of the house and up the toilet open toilet pipe? Also - during construction, the pipes we are talking about (toilet drain, bathroom drain, dishwasher drain were all replaced (not sewer line) in the back of the house and at all times they were dry. We continued using the front bathroom and never had any water flowing to the back of the house. No wall of a sudden, we do have waste water coming from the front bath to the rear bath and out the toilet pipe. If I cap the toilet pipe, will this remedy the issue until we are ready to install the toilet, or is there probably a blockage someplace else in the old plumbing in the front of the house? Thank you.

We noticed the drain in the basement with some standing water that hadn't been there before. There is a PVC pipe coming from the furnace and humidifier to allow condensation to run off and into the drain. I assumed a clogged drain--either too much condensation draining or water backing up from below. When I pulled off the cover, I found some kind of plug...black round rubber grommet with a white plastic cover. The white plastic cover had been broken slightly to allow for the condensation to run down the drain. Too much dirt had accumulated on top of the plug and blocked the small opening so the water had backed up. While I'm happy that the fix was simple, I'm perplexed at the plug. Why put this plug in and then break it slightly to allow for condensation run-off? I have seen plugs designed to let water out, but not in (some kind of float in the plug), but this has me wondering. We've been in the house for 3 years with no problems, so I'll probably just let it be, but would like to address my curiosity. Here's a pic of the drain: [url=http://yfrog.com/ehimag0005xsj]yfrog.com/ehimag0005xsj[/url] Help is appreciated!