I've recently purchased a house and am now learning all the ins and outs of home maintenance. This summer, I've noticed that I have a very smelly basement drain. Particularly, it smells like sewage.
I figured that this wasn't a problem, in that the majority of things I've read state that it simply needs to have water poured in (with or without Mr. Clean) to replace the dried out water in the trap.
This worked fine last year, however this year the smell is back, and far worse. Now, I am essentially pouring water down the pipe every other day to flush the smell. The problem, however, is that it is also ridiculously hot where I am, so we have to run the A/C quite often. As the drain stinks up the basement, that lovely smell gets pulled into the A/C ducts in the basement and then vented throughout the house.
My question is....is this common for this sort of drain? I can't really get my hand into the pipe itself (probably about 3in in diameter), so I can't really see if there is a plug that needs to be checked. I hesitate to call a plumber if it is trivial, but the persistent poo smell is starting to drive us nuts.
Edit
My wife and I went through the house, flushing toilets and watching the water in the drains. Not a ripple for any flushes.
Second edit
Flushed down some Mr. Clean / water mixture and, while it kept the smell at bay for a few days, it is starting to come back. I believe that a plumber is definitely in our future, as I've exhausted the helpful advice provided.