Draining issue - from bad to worse

[Bodrey]

Hi All,

I was having a problem with my kitchen sinks draining properly. I realized that my pipe configuration was incorrect when I started looking up videos on YouTube, and that was likely contributing to the problem. So, I pulled it all out and re-configured it yesterday.

I just finished a load of dishes and expected the sink to drain quickly. Well, instead of the water draining (left sink) the water started backing up into the right sink until there was an even amount of water in the bottom of both sinks (3-4"). What gives... I am so confused right now. I don't understand why the problem has gotten worse, not better.

This is a pic of what my setup looks like...





Could I please have some plumbing pros provide some insight as to what the problem could be? TIA

[Alpha]

Hey, not a pro here but it looks like you have a vent pipe in the top left and what might be a garbage disposal unit, although I’m not completely sure. Since you mentioned that water is backing up evenly into both sinks, that usually means there’s a clog or restriction somewhere after the point where both drains join, so the water has nowhere to go and backs up into both sides. The problem could also be caused by the horizontal pipe connecting both drains not having enough slope. The slope is important because drain pipes need a slight downward angle to help water flow smoothly by gravity. If the pipe is flat or going uphill, water can get stuck or drain slowly causing backups. It might help to check the disposal for any jams, make sure the pipes have that slight downward slope, and look for any blockages in the trap or drain line. Also, if possible, confirm that the vent pipe is open and working properly. Hopefully, fixing these things will help your sinks drain better.

[Bodrey]

Alpha, I do have an ACC installed in the top left. However, I just installed that - the drainage issue was there prior to adding the ACC. I don't have a garbage disposal unit. I will definitely check the slope, but could that alone be capable of causing the sinks not to drain properly? I have a strong suspicion that the clog is further downstream. A poster on another forum also thinks this is the most likely case. I cleared out the P-trap when I rejigged the system. Next week, I plan to install a clean-out (to allow future access should the pipes become clogged again) and also auger it in both directions at the same time.

[Alpha]

Thanks for the update and clarification. Good to know the AAV was added later. You’re probably right that the clog is further downstream, especially since the P-trap is already clean. Water backing up evenly into both sinks usually points to a blockage past where the drains meet, likely in the pipe going into the wall or further down the line. While poor slope can slow drainage and contribute to buildup over time, a full backup like this is more often caused by an actual clog blocking the flow. Your plan to add a clean-out and auger in both directions sounds like a smart move and should help you locate and clear whatever’s causing the blockage. Hope it clears things up. Let us know how it goes!

[Bodrey]

Well, I installed the clean-out today and augered the pipe in the basement. I just did my first load of dishes since the sink backed up last week. The blockage is still there! It does drain faster than it did before but initially both sinks still back up with a few inches of water. I'll have to try augering again but if that doesn't work I don't know what else to do. 😡

[Alpha]

Hey again, sorry to hear the augering didn't fully fix it, but the fact that it's draining faster is a good sign. That usually means you cleared part of the clog, but there's still something deeper in the line.

Try running the auger farther this time and be a bit more aggressive with it. When you hit resistance, work it back and forth and rotate it in both directions. If your current auger isn’t long enough or isn’t cutting through well, you might need a longer or heavier-duty one. Also, try going at it from both the clean-out and through the sink by removing the P-trap and feeding it into the wall. Coming at it from multiple angles can help break up tougher blockages more effectively.

After augering, run hot water for several minutes to flush out anything loosened. You could also try an enzyme-based cleaner overnight to help with any remaining organic buildup. Just keep in mind these work best on softer material and won't fix a full blockage.

If you hear gurgling when the sink drains, that could point to a venting issue, even with the AAV installed, so it's worth checking that too.

If another round of augering doesn't do the trick, it might be time to bring in a plumber with a camera to inspect the line. But since you're seeing some improvement, you're probably close. Keep at it and let us know how it goes.

[Bodrey]

Hi Alpha,

I removed the ACC this morning and poured some Drano Foamer directly into that section of pipe that leads directly to the basement. I suspect that the clog is close and if it was in the elbow that the Drano would remove the clog. I waited an hour for it to do its thing and flushed it with a kettle of boiling water. A little while later I removed the clean-out cap and re-augered in both directions. Just going by feel, I didn't sense that there were any apparent blockages. That said, I'm not going to waste a sink of water just for the sake of testing whether the clog has been cleared. I'll wait until I have to wash a load of dishes again and then see if there's any improvement. Expect another update in the next few days...

[Alpha]

You’ve definitely been putting in the work. Hopefully this latest round clears things up for good. Sometimes these clogs take a few tries to fully break down. Let’s hope you notice a real difference next time you run the sink. Keep us posted.

[Bodrey]

I was able to remove some more of the sludge from the pipe today, but there must still be a solid blockage somewhere. The sink is still backing up. I don't get it - I have to be overlooking something. Next, I'm going to buy (or borrow) a pressure washer and a sewer jetter kit to blast the lines. I've been wanting to buy a pressure washer for years now (to wash the car with a foam blaster) but also to remove the mold/algae on the siding. Now I have a third reason to buy one.

[Alpha]

Since you've augered multiple times without hitting a solid obstruction, it's possible the clog is something that's coating the inside of the pipe rather than a single blockage. A buildup of grease and soap scum can gradually narrow the pipe diameter without fully blocking it. A jetter should handle that kind of buildup well.

When you use the pressure washer, start with lower pressure and work your way up to avoid damaging older pipes. Work it in both directions from the clean-out and let the jetter pull itself into the pipe as the water jets backward.

If the jetter doesn't solve it, or if you find the pipe is clear but the problem still persists, it might be worth double-checking the vent system. Sometimes drainage issues that seem like clogs are actually venting problems in disguise, especially if water drains slowly or backs up evenly between both sinks.

Either way, it sounds like you'll get good use out of that pressure washer for your car and siding too, so it's a worthwhile investment. Hope it works out, definitely let us know how it goes.

[Bodrey]

I jetted the pipe in the basement this afternoon. I don't know if the pipe just wasn't that clogged to begin with or the pressure washer wasn't powerful enough to dislodge anything, but very little 'crud' was washed out of the clean-out. In addition, because of the thickness of the hose and attachments I was only able to jet the straight section of pipe. It wouldn't fit through the elbows. So, its use was unfortunately limited. Alas, my efforts were in vain - the blockage is STILL there.

The kitchen sinks back up fast when I run water which makes me think that the blockage is closer than I realize. I'm starting to suspect that I'm overlooking something. The only section of pipe between the P-trap under the sink and the clean-out in the basement that I'm unsure about is the first elbow that connects to the straightaway. However, I poured Drano Foamer directly into the section of pipe that leads directly to the elbow, let it sit for an hour, and flushed it with hot water... but the sinks are still backing up. If there was a blockage at the elbow and that Drano was even half decent I should have at least seen some improvement.

So, I'm ready to admit defeat and hire a plumber. I know it's going to cost me dearly, but I'm out of ideas. I don't know what else I can do. After all the effort I've put in to fix this problem I can't believe that the blockage is still there. I just don't get it...

[Alpha]

I completely understand your frustration. You’ve done a lot to try to fix this, and calling a plumber now is the right next step when you’ve tried everything you reasonably can. A professional will have the tools and experience to spot issues that aren’t easy to detect, like hidden blockages, poor slope, or pipe damage.

The work you’ve already done may actually help the plumber solve the problem faster. Please keep us updated on what they find. I’m genuinely interested to know what the cause is.