My washer uses the same drain pipe as a toilet in a Jack & Jill bathroom that I frequent since it is off from the bedroom I use as my office. When the washer drains the water level in the toilet bowl drops a little. The more washing the more draining the lower the water level in the toilet bowl. This has been going on for about 6-12 months or so. Now, couple this observation with something I watched on the television.
This past Saturday I watched an episode of Ask This Old House and Tom Silva visits a homeowner that had a similar problem in which two toilets (one upstairs and one downstairs) shared the same vent stack. The homeowner noticed that whenever toilet upstairs got used the water level in the downstairs toilet dropped. Being that the upstairs toilet got used much more often than the downstairs, the level dropped to a discouraging amount–it wouldn’t work properly under this condition.
So, Tom went to the roof with a optical probe and discovered the vent stack had become plugged above where the second floor toil drains, and during a draining activity for the upstair’s toilet it would create vacuum on the drain leading to the downstairs toilet, which was relieved (no pun intended) by pulling down the water in that bowl.
Tom removed the obstruction and everything work as normal. At this point I got to thinking about my Jack & Jill toilet and how the water level in the bowl drops whenever the washer drains and wondered if the stack for these two drains happens to be plugged. Now, my neighborhood is only 5-6 years old and the trees in the neighborhood about the same age. The organic debris from neighborhood trees would literally have to defy gravity by 20-30 feet to get to the stacks in any of the homes.
Then I got to thinking about bird or rodent, etc., but there is no way I’m going on that roof (its scary!). Ideas? Also, could an undersized or inefficiently designed/installed plumbing also aggrevate this condition? I’ve noticed the ‘flow’ of water from toilet tank through bowl in the toilet in the master bath leaves little to confidence, too. And whenever that one flushes I hear under-sink wet-traps (I think) make noise.
Replies
Plugged vent stacks are really far rarer than many folks would have you believe. The most common cause of plugging is frost, but that obviously only occurs in winter. Otherwise it would be a bird's nest or tree debris or some such.
There is one other possibility, in a relatively new house: The vent may never have been connected in the first place, or may be plugged with a test plug. If your vent is plugged then this is the most likely possibility.
It's a little hard to say from your description whether you might have a problem. A slight oscillation of the water level in a toilet is normal when another toilet is flushed or some such. If you feel it's a problem, and you don't want to get up on the roof yourself, then perhaps the best thing to do is to pay the $100 or so it will cost to have a plumber check it out. (Or, if there is a handyman service available, that might be a slightly cheaper alternative.)
Edited 9/13/2005 11:11 am ET by DanH
Nuke,
I think DanH is on the right track -- my vote is for the test plug left in place which may be a builder's warranty issue ( I got the impression the home is relatively new).
Another cause would be an undersized vent (unlikely).
The undersink traps making noise is a definite clue pointing to vent problems of one sort or another. I would temporarily remove the under sink traps to give unimpeded venting and try a few test flushes -- see what happens. Does the bowl occilation cease or diminish? Toilet flush better? If the answer is yes then there is something obstructing the vent stack -- test plug or other stuff.
Short of getting on the roof, I don't know how to inspect a stack, although I guess if the stack was PVC you could cut the vent stack in the attic and inspect with a mirror then cement in a coupling to repair the vent stack.
A trip to the attic might be informative as many of our local plumbers insert their test plugs in a convenient T fitting in the attic and like DanH said the plug may still be there with the last run of pipe sitting alongside of it or even resting on top of it, if this is the case just lift the pipe, remove the plug ( generally a wing nut) and cement the pipe into the fitting.
Jim
Never underestimate the value of a sharp pencil or good light.
What's a "Jack & Jill" toilet?
Kate, a Jack & Jill bathroom is an affectionate way to describe a bathroom when there is two access doors and they both lead to bedrooms and not a hallway. Two of my four bedrooms share, exclusively, a J&J bathroom, and the other two bedrooms have their own baths.
Curley, nature is funny AND stupid.
JTC1, the problem evolved over time. If it were a test plug left in place (as DanH) described it could be, then I should have seen this from the beginning. This isn't the case.
Edited 9/14/2005 7:55 am ET by Nuke
Problem evolved = some obstruction other than a test plug.
Yank the undersink traps and flush the toilet - problem gets better = vent obstuction problem; not get better = drain line obstruction problem ( doubtful due to the reported gurgles from traps when flushing; gurgle usually means clear drain that cannot get enough vent air).
Go on roof or cut vent line in attic and rod out - up and down both for inside of attic access. You will probably be able to do at least a partial visual inspection with the aid of a small flashlight and a mirror.
Flush a few times for test purposes - install coupling to repair the vent line.
Good luck.
Jim
Never underestimate the value of a sharp pencil or good light.
Every year before I fire up the wood stove in the garage, I got to get the dead birds out of the burner. Why the birds go down my stove stack is beyond me. If they'll go down the stove stack, maybe the same for a vent stack
dennis
That's interesting. I saw the same episode (I think), but it was Richard Trethewey (sp?) on the roof with that nifty optical gizmo - lol. Whoever it was, the fix was real.
I found and fixed a similar problem once. No optical gadgets, but on a hunch I ran an electricians fish tape down a vent. There was a slight obstruction about 5' down that went away when I "bumped" it a couple of times. I have no idea what it was but the problem disappeared.