huge bubble up from drain when i flush toilet

[sparks n arcs]

Hi all,

When I flush the toilet a huge bubble comes up from the bottom of the bowl. This happens even if there is clean water in the bowl. Other than this the toilet flushes fine. (American Standard toilet).

The toilet in question is on the main floor of a 1 story house. House does have a basement. This is the only bathroom in the entire house. I had a plumber run a camera from the cleanout in the basement through the main drain 2 months ago, (I purchased the house 2 months ago) and no blockages or breaks were visible. The camera made it all the way to the main sewer. House was built in 1958.

My first guess would be a venting problem, but I am very uneducated when it comes to venting systems.

Second guess would be a partial blockage in the drain line between the toilet in question and the accessible cleanout of the main drain.

These are truly guesses as I really don't have a clue.

Any help would be greatly appreciated.

[Mike Swearingen]

If you're certain that the main drain line is clear, you're going to have to check the built-in trap of the toilet with a toilet auger to clear it, and/or pull the toilet and snake the closet bend.
This sounds like a clog before the main drain line, probably in the closet bend. I don't think that it's the vent.
Replace the wax ring, of course, after you pull the toilet, and you'll probably need to replace the two brass toilet bolts, too.
If you need a step-by-step how-to on pulling and replacing a toilet, just ask. That's what we're here for.
Good Luck!
Mike

[sparks n arcs]

Thanks for the suggestion.

I will be able to pull the toilet and replace the wax ring. If I am understanding right, I should snake from the bottom of the toilet up to the bowl. Would this be different than from trying to snake from the bowl down? Also, should I snake from the toilet flange down the pipe until it reaches the cleanout plug in the basement?

Thanks again, I really appreciate (need :D) the help.

[majakdragon]

If you pull the toilet, you should be able to look up into the toilet trap for blockages. A closet auger has a plastic protector on it so it does not damage the toilet finish as would a plain snake. After you check the toilet trap, run the snake down the piping to clear any clogs there may be in the rest of the piping to the cleanout. Good luck.