I have a slow drain issue I’m looking for some ideas on.
In one wing of the house we have a guest bath and a master bath. Both of these bathrooms have the tub/sink/toilet drain into a 4″ line. The master bath line runs about 20′ while the guest bath runs about 10′ till they merge and exit the house.
The problem is a slow toilet in the guest bath. If I flush the master toilet I will get bubbles coming up in the toilet in the guest bath along with the water level fluctuating slightly. Also when draining the tub in the guest bath we get bubbles and water level fluctautions in the toilet and the tub drains slowly. When flushing the guest toilet it acts plugged but just fills up and drains slowly.
Any idea on a cause and what I can do to fix? The masterbath toilet/tub every thing drains fine. I could understand a slow drain but I don’t understand the whole bubble issue.
Thanks in advance for any help.
Replies
Birds nest in the vent stack will do that.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
I was just on a roof where two of the three stacks had the plastic test plugs still in. Was left that way for 3 yrs.
John Svenson, builder, remodeler, NE Ohio
if you are on a septic tank it may be time to get it pumped
It's vaguely possible it's a vent problem, but sure sounds like a clogged line or an overflowing septic.
"It's vaguely possible it's a vent problem, but sure sounds like a clogged line or an overflowing septic."How do you explain no problems in the master bath if it's an overflowing septic?John Svenson, builder, remodeler, NE Ohio
Do you know where the main waste pipe exits the foundation? Overfilled septic problems usually start there and work progressively into the house. It's possible that the master bath is upstream of the guest bath.
I think it could also be a blockage in the guest bath. Any guests been flushing anything weird?
Scott.
Edited 2/25/2009 11:14 pm by Scott
Has all the signs of a vent issue.
If it was vented properly the water in the toilet would not be disturbed by the use of any other fixture.
I've been wondering about it being a vent issue. The master bath vent runs up thru the attic and tie's into the vent from the guest bath before it exits the roof. At least that is my assumption since there is no vent stack above the master bath. I will look in the attic tonight.
I've thought about the idea of the septic being full but it's only been 1 1/2 years since it was pumped. We also have an alarm on it that is not sounding. And, the 1/2 bath and laundryroom is much closer to the septic than the other baths and we are having no issues there.
One thing I did notice last night, after monkeying around with the plunger and trying to feed a snake down the toilet, is that when we finally went to bed that the water level in the toilet was very low in the guest bath.
As far as guests flushing anything wierd, it's the kids bathroom so who knows what they may have flushed.
Maybe I'll climb up on the roof tonight and look down the vent.
>>>it's the kids bathroom so who knows what they may have flushed.Uh Oh.... I've had that one. It's a classic. A kids toy will cause this problem. Get yourself a dentist's mirror (preferably one that a dentist doesn't plan to use again) and have a look upwards from the bowl to the trap. You might just see something......Scott.
"...when we finally went to bed that the water level in the toilet was very low in the guest bath."Yeah, does indeed sound like a vent problem. A few weeks back, at a weekend place up in NH, I had the problem with the toilet chugging as it flushed. Occasionally, with no drain activity going on in the house at all, I would hear the sink drains and toilet chugging as air was being sucked past the traps. The toilet level wound up very low.The vent pipe in that place runs up the outside of the building, through the roof overhang, and up maybe a foot. It's, I think, a 3" vent. The snow on the roof was at the top of the pipe. I think that with the pipe being outside of the building envelope it was getting clogged with frost and snow falling down the pipe.Also, the overflow from the septic tank goes to a holding tank, from which it is pumped uphill to the leach field. I do know there is some leakage of ground water into the holding tank. Once in a while, as the level slowly rises, the pump will come on and pump out liquid. This requires replacing that volume with air, which normally comes down the vent pipe.So, the occasional chugging I heard and the dropping of the toilet level was due to the pumping of the holding tank. The next day the outside air temperature went up to near 40, the vent pipe defrosted, and things were back to normal.
Your description of the problem indicates improper venting of the master bath.
You can eliminate septic tank considerations as being the problem as well as blocked or partially blocked lines. If either of those were the case, you would be having slow drain problems with all the fixtures.
What appears to be happening is that when the toilet or tub in the guest bath sends a slug of waste water (and/or suds) into the drain line above the master bath, the drain line fills enough to "push" air pressure ahead of itself, and this pressure is enough to burp the traps in the master bath. Then, after the slug of drain water passes beyond the branch drain opening where the master bath ties in, the slug of water begins to "pull" a negative pressure behind itself, which is the cause of sucking out the the trap seal of the toilet.
The effects of such pushing and pulling (positive and negative pressures) are neutralized, or relieved, by properly located and installed vents. That's why vents are always supposed to be just downstream of the trap they protect: any pressure changes are relieved in the vent before such pressures can affect the trap seal. This is also why all vents are supposed to take off in the vertical and remain vertical until they get at least 6" above the flood-rim of the fixture they serve. If they turn horizontal at any point lower than the flood-rim, there's the risk that the residue of solids left behind from a blocked or over-filled drain will back up in the horizontal portion of the vent and eventually cut off the vent's ability to relieve pressure differences.
If you have access (like a crawl space or basement)to the drains and vent take-offs, you might be able to locate the problem and fix it. It is almost impossible from where I sit to tell you definitely and exactly what the problem is, but I hope that understanding how vents are supposed to work will help you figure it out. Best of luck!
how about explaining vent cross sectional
"how about explaining vent cross sectional"
Sure, if you could tell me a little more about your question. I'm not sure what you're asking.
i thought if you could explaine how the total vent cross sectional exiting the roof equales the total waste pipe cross sectional exiting the building , this might give a larger understanding ,and evaluation of the problem for diagnoseing the problem . ienjoy reading your responses ,i always seem to learn and understand more from reading them
The two dominant plumbing codes in the country right now are the IPC (International Plumbing Code) and the UPC (Uniform Plumbing Code), and they differ as to what is required for the vent areas.
The UPC requires that the combined cross-sectional area of the vents through the roof must equal the cross-sectional area of required drain. Thus, a house with up to 3 toilets would require a 3" drain, and the cross-sectional requirement for the vents would be that their total would equal that area.
For example, a single 3" VTR (vent through the roof) would obviously meet the requirement, as would the combination of 2 two-inch vents plus 1 one-and-a-half-inch vent. But the combined cross-sectional area of 1 two-inch vent plus 2 one-and-a-half-inch vents would not quite be enough.
The UPC requirement is overkill, but it does no harm except for a small increase in cost.
The IPC takes a different approach, and has tables for arriving at the needed vent size. These tables actually take into consideration the fact that there are really only two factors that affect vent sizing: 1) the drainage fixture unit load, and 2) the effect that the length of the vent pipe has due to the increasing friction as the vent gets longer.
Thus, using the IPC, a house having 3 full baths, a kitchen sink, washing machine and a floor drain would have a fixture unit load totaling 21. (5 for each bathroom group, 2 each for the sink, washer and floor drain.) Table 916.1 of the IPC shows that the entire 21 fixture units could be vented using 1-1/2" pipe, if the developed length of the vent is 32 feet or less. If the developed length of the vent is over 32 feet, but not over 110 feet, then a 2" vent would suffice. This might seem small, but the IPC requirements are based on sound principles of physics. Just think of how small a vent hole is needed in a jerry can to admit all the air needed to accommodate the flow out of the 2-1/2" lid. Also, the IPC takes into account the fact that never will all the fixtures in the house be drained simultaneously.
These differences illustrate the inconsistency and sometimes irrationality of our current plumbing codes. There is much, much more, with defects in both codes, but I've probably already put you to sleep with this lengthy, boring harangue. All of us should be clamoring for the development of one nationally-accepted code that is based on solid technical information and not influenced by special interests such as manufacturers, labor, old plumbers' pet peeves, etc.
You forgot to mention that in northern climes the vent is supposed to get larger as it exits the roof.
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
Well, thought I'd respond to what solved my problem. I went on roof and looked at vents and they were fine. Still only having issue with the guest/kids bathroom. All other fixtures on main floor were fine. Then last night as I was downstairs adding salt to the water softener, I noticed drips coming from the cleanout cover for the plumbing on the other end of the house. Well the only way that should leak is if it was full and it would only be full if the septic was full. So i went out and looked and sure enough, it was full. Earlier this winter my 6 yr old son had hit the post that holds the power supply for the pump in the tank with his snowmobile. I stood it back up but didn't look inside the box. So when I opened the box this time I saw he'd hit it hard enough to unplag the pump to the mound. Once I plugged that back in, the pump kicked in and now all is good. Bathrooms all work fine last night and hopefully that problem is behind me.
thanks for all the good advice. Now I just need to figure out why my level alarm in the septic tank didn't work.