AboutSharon McCarthy Expertise I can help with most questions about residential plumbing problems including septic systems, and some questions about irrigation. I have no experience with commercial installations or codes.
Experience I have been a sole-proprietor service plumber in two small towns north of Phoenix Arizona for 26 years.
Publications I had a monthly column in the United Steelworkers of America, local 1033, newsletter 1978 to 1982. I wrote an article for "The Theosophist" in 1977. I've written dozens of letters to the editor in many newspapers.
Education/Credentials High school and three years of college. My step-father, having worked 40 years in the plumbing trade in Chicago, taught me for two years. The rest has been hands-on experience.
Past/Present Clients Many hundreds of good people in Cave Creek and Carefree Arizona
Question QUESTION: Hi Sharon,
I have a rancher built in 1991 with a walkout basement, two toilets upstairs, one in the master bedroom and one in a powder room these were "new" 5 years ago. Two toilets downstairs, one in a bedroom and one in a powder room. The two downstairs toilets were added 4 years ago to code. All the toilets are Elger Titan low flow except the one in the lower powder room which is an American Standard low flow.
When the upstairs powder room toilet is flushed the lower powder room toilet burps....large bubble of air. When either of the other toilets are flushed there is no burp anywhere else.
All the toilets flush very well (other than this burping problem). I have gone on the roof and run water down the venting system so I don't think that there are any plugged vents.
Any comments or ideas would be appreciated.
Thanks, bob
ANSWER: Dear Bob,
I've been sitting here staring off into the distance trying to picture this whole set-up, and why that bubble would come up in the lower toilet. I imagine the toilet upstairs is right on the same line with the one downstairs.
That may not necessarily be a bubble of air, it may be a bubble of water. One possibility is that there may be some partial blockage just past the toilet downstairs that stalls the flow of water from above, and a little bit backs up until the water finally gets through.
Question: is this recent, or has it been happening since the downstairs toilet was put in four years ago? If it's been happening all along, that might have a different explanation altogether.
Is the downstairs part of the walk-out basement? I'm just wondering if the pipe leaving the downstairs toilet goes "down" to a basement, or if it bends at a 90 degree angle just below the flange.
If it does bend, then I wonder if the water dropping down from above, which would be flowing pretty fast, hits that bend and stalls a bit before it can all flow out.
Most of the toilets in my area are set on a slab, we don't have many basements here because the soil is so hard. So all the 3" pipes under the toilets have a 90 bend on them less than a foot down from the floor level. This never causes a problem, because the water just flows out from the bowl, it's not dropping from 12 feet above at an accelerated speed.
I'm only speculating. If the bubbling is recent, then I'd say it's a partial blockage. Rarely, in my experience, is the problem in the vent. Let me know what you think, OK? sharon
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QUESTION: Hi Sharon,
I seem to be having problems answering your questions but I will give it another go.
No the downstairs toilet in not on the same line but it y's into it from about 35 feet away.
If it was water and not air....where would this water be coming from?
It is recent but I can't tell you how long as my wife just mentioned it to me and said that it has been happening "for quite awhile"....like months not years.
The toilet bends at a ninety as the walkout is on a slab.
Thanks for the quick response and ideas.
Bob
Answer Dear Bob,
I was honestly visualizing that the downstairs toilet was just below the upstairs toilet, that they were hooked to the same pipe. 35 feet away is quite a distance.
You mentioned all the new work was done to code, and it sounds like this bubbling began happening recently, so I doubt very much that it's a vent problem.
When I said it might be water bubbling up, picture it this way. The water flushed from upstairs goes down, bends, goes 35 feet and "Y"s into the line of the powder room toilet downstairs. If there is a partial obstruction right past that downstairs toilet, the water traveling from upstairs will hit the obstruction and some of it will rebound back.
This is just theoretical, but it could be what's happening. When some of the water sloshes back, there is more water behind it still coming. The back pressure of the water could conceivably cause a little of it to go UP into the downstairs toilet and cause a burble in the bowl.
This might be the case, it's the only explanation I can think of. There might be some other reason. If this continues and you have no other problems, you can probably let it ride. Whatever is in there, if my theory is correct, will either wash away or build up more, at which time you'll notice the toilets begin flushing more slowly or the water won't go down.
