Bathroom drain line problem: by process of elimination

[The Old Maid]

Toilet/sink/shower have one drain into septic tank.

Day 1: clean water overflowed from toilet. No other symptoms. Used plunger. Some "air" sounds.

Days 2-4: toilet failed to flush if used more than 2 times in a 12-hour period. Eventually subsided. Liquid drain cleaner worked once, then not at all thereafter.

Days 5-7: same as just above, but also with airy, throaty gurgling sounds in the toilet when the shower has run 10 minutes. Failure to turn off shower results in mild backup into tub.

Days 8-10: foul backup into tub, did not use shower and again, only 1-2 flushes. Plunger and drain cleaner do nothing but push from one danger spot to another.

Day 11: after reviewing Terry's Forums, suspected that ventilation stack might have an obstruction. Carefully poured 2 gallons of clean water down root vent stack. Good news: no leaks, plus went straight through. Therefore, vent is not obstructed. Bad news: welled up in tub with foul water i.e., raised the water level again. Waiting for drain to subside before next step.

By process of elimination, this leaves two probable causes. One: the septic tank may be full. Two: the drain has a serious clog.

It's hard to tell if a tank is full. We can only say we have it pumped every few years and we are not heavy water users. Also, the clothes washer is being replaced, so it absolutely has not contributed too much load.

As for the drain, we don't have one of those miniature water-saving toilets, and we don't flush inappropriate materials down the drain.

At this point, we are thinking we will next have the septic tank pumped. After all, if it really is the tank, no amount of plunging, chemicals, or mechanical snaking of the drain line would make a difference. The stuff has to have some place to go.

There are no wrong times to pump a septic tank. Frankly, it's early. But realistically, what are the probabilities that this is the problem, vs. the odds we will still have to snake out the drain line?

For the drain, there are 3 obvious access points: toilet, basement clean-out tap (capped), and outdoors clean-out tap (capped).

Also, at which location should a power snake be initiated? My obvious preference is for the outdoor tap (to keep the mess outside). That is what it is for, after all.

Basically, if the pump-out doesn't work, at which drain access point would you prefer to start?

As a control, there are no known problems with the kitchen drain line into septic tank. If it were the tank, we would think both lines would be backing up. Having said that, the drain is about 10 feet longer.

Thoughts?

 

[Reach4]

Day 11: after reviewing Terry's Forums, suspected that ventilation stack might have an obstruction.

I suspect you mis-read whatever you reviewed.

Therefore, vent is not obstructed. Bad news: welled up in tub with foul water i.e., raised the water level again. Waiting for drain to subside before next step.

By process of elimination, this leaves two probable causes. One: the septic tank may be full. Two: the drain has a serious clog.

It's hard to tell if a tank is full. We can only say we have it pumped every few years and we are not heavy water users. Also, the clothes washer is being replaced, so it absolutely has not contributed too much load.

If the tub is your lowest drain, then your thoughts that it could be either makes sense. How long ago was your last septic tank pumping? Be around, and ask how full the tank was. I hope you have an experienced operator. An independent would be what I would prefer.

Basically, if the pump-out doesn't work, at which drain access point would you prefer to start?

As a control, there are no known problems with the kitchen drain line into septic tank. If it were the tank, we would think both lines would be backing up. Having said that, the drain is about 10 feet longer.

It is mainly about the altitude. Expect the lowest drain before the clog to show symptoms. That would often be a shower or tub, but it could be a floor drain.


You may do well to find a drain cleaning specialist. He will have the bigger equipment, and you could injure yourself if you rent the big stuff. If you do it yourself, I would take into account where it is going to be easier to access and clean up after. You would avoid a cleanout over carpet, for example. You want something upstream of the clog. You would like to have a bigger port.

Do you have an outside cleanout? Sometimes you can look into the port and see if there is standing water.

 

[Sponsor]

 

[The Old Maid]

Thank goodness, we do have outside cleanouts for both the kitchen line and the bathroom line. Haven't had a chance to check them yet.

You mentioned altitude i.e. the lowest drain before the clog. That's what has had us stymied. The toilet misbehaved first. From highest to lowest on the drain: toilet, sink, shower. It took a few days for the shower to get in on the problem. The sink has been slow to drain every few days or so but has never backed up.

Will post more in a few days after weather changes. In the meantime, I'll keep looking in on this thread for comments and suggestions.

 

[Reach4]

You mentioned altitude i.e. the lowest drain before the clog. That's what has had us stymied. The toilet misbehaved first.

That would seem to point to a clog in the toilet or in the line from the toilet.

Maybe some of it rolled downhill.

Maybe a drain specialist could clean most of your drains -- even those which have not exhibited a symptom.

 

[The Old Maid]

New developments.

To ease the strain on the affected drain line, we decided to wash our hair in the kitchen sink, like hippies.

The tub backed up (dirty backup).

The bathroom line and kitchen line are at different angles and have different lengths. The kitchen line is easily twice as long before it exits the building wall. The drains are not parallel. It is possible that they meet, but not likely.

We'll have the septic tank pumped. If it works, well and good. If it doesn't, that theoretically makes the location of the problem clear to within a foot or two of pipeline.

 

[The Old Maid]

Septic tank has been pumped. All drains appear to be functioning normally.

Now we have to figure out why the septic tank seemed to be at capacity an entire two years ahead of schedule. But that's a subject for a different thread.

Thanks to the forums for your help!

 

[Reach4]

Now we have to figure out why the septic tank seemed to be at capacity an entire two years ahead of schedule. But that's a subject for a different thread.

I would schedule your next pumping interval to be no later than half as long as it was this time.

Do you have a garbage disposal?

 

[LLigetfa]

Now we have to figure out why the septic tank seemed to be at capacity an entire two years ahead of schedule.

What do you mean "ahead of schedule"? What schedule? Mine knows no schedule having gone 18 years between pumping.
https://terrylove.com/forums/index.php?threads/this-really-sucks.70681/

Do you only have a holding tank with no percolation field? A holding tank only knows gallons, not years so the faster you fill it the sooner you have to empty it.