Could this be an air vent problem? Our toilet flushes ok, but continues to very gradually draw down the water until it’s just at the drainpipe level, and then it gurgles and belches foul air. Adjusting the toilet tank setting to allow more water to flow through at each flush makes no difference. The water level always creeps down.
The air vent is the appropriate size and connection. It rises vertically for 7′, runs horizontally for 6′, then rises another 3′ through the roof. It would be hard to unplug and I would like to abandon that portion of the run. Can I cut the vent at the bathroom ceiling (or wall near the ceiling) and install a louver there, so it pulls air from the bathroom? How can I keep sewer odor out? Is this allowed by code?
Replies
go to terrylove.com.....they know plumbing stuff there
definetly a venting problem, now that was the easy part, cutting out the existing vent and replacing with another will not likely resolve the issue, less the current vent is plugged. There is too much "suction" in the toilet line drawing the water out of the bowl, sounds like your toilet vent is trying to vent more than just the toilet ..
Right on Wane. I recently added a shower -- properly plumbed into the drain line --and the problem got worse.
I suspect the current vent is clogged in the horizontal run -- there is some drywall damage from moisture -- but don't want to cut into the ceiling as it would be disruptive to the resident. I Have considered snaking it down from the roof, but with two 90d. bends, am concerned that might make matters worse. Therefore thought it might be easier to abandon that horizontal section and work with the existing vertical run. It would be much simpler if I didn't have to run the vent to the exterior (thru the roof).
I appreciate your thoughts on this.
V.
Another possibility:
Since the toilet trap drains "very gradually", you could have something like a small piece of rag or string caught in the weir of the trap that is wicking the water from the trap. The weir is the part of the trap that makes the flow line of the trap, or the point where the water must rise above in order to begin flowing from the trap, so if a string hangs partially in the trap and up over the weir, it can act as a wick to gradually drain the trap. If this is the problem, a toilet auger should pick it up when you run it thru the trap while cranking the handle. A toilet plunger would probably not do the trick.
Well, what a mess. And we don’t have enough info to help.
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From the OP, I figured this was a plugged vent and maintenance issue. But even then we didn’t really get any info on the layout of drains, vents, and fixtures. I wondered why changing an existing (perhaps previously working) vent was better than clearing it.
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Then Varch allows in another post that he has added a shower to the drain system. Well, did it get vented properly? Or if Varch did the original vent install, maybe it runs downhill just enough to become (partially) blocked with water from rain or snow from above. So maybe it’s a design deficiency.
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Varch, don’t make additions or changes to your plumbing unless you know what is required. Never vent into your house. My advice is get a plumber.
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Jim x 3
i agree the problem sounds like a clog , i might add that a studder is not recomended for use on toilets be it a septic or sewer .
Yeah, that's at least a vague possibility.
The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
Thank you everyone, for your thoughts on this.
More background: House is older, remodeled 20 yrs ago, to code. Plumbing was done to code. Newer shower installed to code. Septic system has been eliminated as the problem. Old toilet recently replaced, so know that the trap and weir are clear. The toilet flushes great -- but then the water keeps on slowly oozing down past the normal level until it's low enough for air to push its way up out of the drain and bubble out. The water acts like it's being drawn down, (siphoning effect?) Running water down the drain of the lav or shower aggravates the problem.
My mech guy thinks it's the air vent. His suggestion: cut the air vent high in the wall, then flush toilet with the vent open to the air, then closed off, and see if it has solved the problem. If that works, then install a "StudorVent" (sp?) that allows air to enter the vent pipe but blocks air that comes up from the drain. This is allowed by code in our state, Colorado, as long as the vent has a vertical rise that takes it above the rim of the highest fixture (lav, in my case, but I will actually take it up to 7'). Last, install a grille over the hole in the drywall.
Opinions? thoughts?
Thanks, Varch
Don't use a studor vent (AAV or Air Admittance Valve) on a toilet. Even if they are allowed they occasionally fail and you will be getting another repair call. Normally AAVs are only used when it is very difficult or impossible to vent a fixture properly.
You already have a vent - assuming it was correctly installed - all you need to do is clean it.
If you can access the vent pipe in the attic go up there, cut the pipe, and snake it down and up and then install a coupling to rejoin the cut pipe. The snake should be able to go around 90s with out much problem. If you can't get to it in the attic and the roof is difficult, cut a hole in the wall as you said previously. If you can't do any of that, call a roto-router or similar.
BTW - I don't think you said - is the pipe PVC (white plastic), ABS (black plastic) or what? Also, what (inside) diameter do you think is it?
One possibility is that the toilet is defective. It's not unheard of to have a defective toilet bowl where there is a leak from the bowl to the drain, without going over the weir.I can't see endorsing the Studor fix when the vent OUGHT to work, and at worst just needs to be rodded out.
The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness. -John Kenneth Galbraith
You absolutely do not want the vent of your stack louvred to the bathroom. Ever been on a roof near one of these things. They don't always smell but often they do. Unless you are on your own septic, that aroma can be venting from the main as they are not typically vented and rely on the houses for that.
Sounds like a bird or squirrel has lodged inside. A couple cuts, two couplers and you should be back in business. The belching foul air is an indication that fresh air is having a difficult time entering the system. Is there a neigbouring sink or shower showing similar difficulty draining?
HAve a good day
Cliffy
"It rises vertically for 7 feet..."
My question: does the vent actually take off from the top side of drain line in a true vertical postition? It should. If not, the portion that is not vertical will collect solids/residue over time, and mold and other nasty stuff grows in along with it to eventually block off the venting ability.
Of course, if the toilet vent is a "wet vent", that is, if it is also serving as the drain for a fixture above, such as the lavatory, then the vent will continually be washed by the drainage of the upper fixture. The main thing is that, at whatever point the vent becomes "dry", that point must be in the vertical (not less than 45 degrees above horizontal), and must continue to rise in the vertical to a point at least 6" above the flood rim (say, the countertop where the lavatory is mounted) before turning horzontal. Thus, even when the drain line is blocked, sewage can't rise to a point where it would find its way into the horizontal line where residual solids will be left behind to eventually block the vent.
If the vent take off is truly in the vertical, you'll have to look elsewhere for the problem.
You can test by sponging all the water out of the toilet trap, and put in about a tablespoonful of peppermint oil in the bottom of the trap; have somebody blow air with a leaf blower into the toilet trap (wrap around it with rags to help seal the airflow), and go up on the roof to the vent termination to feel if air is flowing out. The air will tend naturally to rise in the vent more than it will go down the drain system, so you'll be able to effectively detect airflow, and smell the peppermint oil as well.
If the vent is blocked, air with peppermint aroma will burble up out of other traps in the bathroom, like the lavatory or tub.
As others mentioned, do not louver the vent into the living space, or even into the attic.
In the worst case, you may need to add an air admittance valve in an accessible place, like under the lavatory cabinet. AAV's can fail in time, so they need to be accessible. The AAV will allow air into the drain system, thereby protecting the traps from siphoning. You would add the AAV downstream of the trap.
Probably a venting problem of some sort. Could be improper venting from the start (has this problem always occurred?), a plugged vent, or wind action across the vent pipe on the roof. It's also vaguely possible that the problem is excess pressure in the house (though you'd then generally experience the problem in other drains, and you'd likely feel your ears "popping" a bit).
If this is a new house, one fairly common problem is the failure of the plumber to remove the test seal from the vent pipe on the roof.
The length of vent run you describe is not unusual, and isn't likely to be a problem, with one exception: If the horizontal run is not slightly sloped towards the drain then water could collect in there and cause problems.
You should not cut the vent pipe and let it vent to the inside, since this would bring the foul air you're experiencing into the house all the time.
Give us some history: Old house or new? Has this problem been there "forever", or did it recently develop? Where do you live (and how cold has it been recently)?
>> If this is a new house, one fairly common problem is the failure of the plumber to remove the test seal from the vent pipe on the roof. <<
Not sure how it is doen in other states but here no text plug is used on the vent(s). The system is tested by plugging all future points of fixture connections, and installing a test stack on the top floor, typically on a waste pipe for a future lavitory. The test stack is typically 3 or 4' tall. A plug is installed at the south end of the system, typically outside the house where the drain pipe exits. The system is then filled with water up to the top of the temp stack. The test is required to hold for 24 hrs.