arrow is pointing to the access where water can be seen freely flowing from the sink.No other drains in the house are slow or backing up, but my kitchen sink fills and won't drain properly. We've run a 25ft snake down the pipe from inside the house (under the sink at arrow) and from the air vent on the roof, but haven't found any clogs. When my husband took off the cap (at arrow) under the sink, he could see water flowing freely through the opening when he turned on the faucet. It only takes two (electric) kettle fulls of water to have water backed up into the sink, though. I only mentioned electric kettle to relate its size and the amount of water it takes to back up the sink again. It takes more than an hour to drain completely when there's about 3-4 inches of water in each side of the sink. We have used a couple of different drain cleaners over the last few days trying to clear the blockage, but nothing is working so far.

I hope these added details help clarify any questions.

  • How far is the kitchen sink from the main drain/air vent line? If further than 25 feet then might need a longer snake. If closer this is weird.
    – crip659
    Oct 25, 2022 at 18:51
  • 1
    Please edit your question to clarify a few points. 1) What do you mean about seeing water flowing with the "cap off"? What cap? How can you see water flowing inside a plastic or metal drain pipe? How does water get there if it's disassembled? Photos would help, you can edit your question and add them. 2) What's the relevance of the kettle and of it's being electric? Why are you using a kettle to diagnose your drain? 3) 25 feet of 2-inch pipe is 4 gallons of water, a lot more than two kettles. So, IDK about the blockage being further. We may need more info. 4) Is it draining slowly?
    – jay613
    Oct 25, 2022 at 19:02
  • 1
    Snake can be tricky. Instead going down the drain, it might just go up in the vent line
    – Traveler
    Oct 25, 2022 at 19:56
  • You should always be able to edit your own questions. Since your edit went into the approval queue, it's obvious that you've accidentally created a 2nd account. Please follow these instructions to get the two accounts merged. It'll make your life much easier.
    – FreeMan
    Oct 25, 2022 at 23:35
  • Not a plumber but it seems obvious that there is a connection between the lower-capped pipe and the drain. Is water backing up from the lower-capped pipe to the drain? If you were able to shoot water in the lower pipe, would you find water coming up in the sink? Done my fair share of DIY drain work, never seem two random capped pipes by the drain. Any plumbers out there know what these could be? The pipes are all in perfect alignment, so suspect they connect to the same trunk pipe?
    – Chris
    Oct 26, 2022 at 0:27

2 Answers 2


The drain cap under the sink may be passed the clog. 2 kettles of water I would assume may amount to a gallon or so. This means the clog is not too far. Remove the p-trap and look directly and feed the snake into the pipe.
You can also purchase a pressure water feed that goes into that drain pipe. It fits on a gardon hose, feed it in that pipe and Turn the water on The mechanism is rubber and it responds to the pressurized water and it expands against the wall of the pipe and blust off whatever is there.

I hope this helps. Take care.

Did you take the P trap out? See pic?


p trap


We don't know what D and E are. They may have nothing to do with this sink, or at least nothing to do with this blockage. They may be drains for a second sink or dishwasher that were removed. Looks like you have a typical double-sink drain arrangement (top of the photo) but maybe once there were separate drains to two sinks.

Anyway ... if you have access to what is inside that wall or the basement ceiling just below it, you might get some clue what those two pipes are but it doesn't matter. For now:

  1. Remove the trap at points A and B, and the elbow at C, and make sure those little pieces aren't blocked. They are the most likely place for a blockage.
  2. If that doesn't solve it, snake from point C.
  3. That oughta do it.

enter image description here

  • 1
    We removed the p trap and 90° elbow. They were completely clear. We used a water pressure bladder to snake from 'E' (because C, D, and E are all off the same downflow pipe), and that cleared the blockage. We could hear the water building up pressure in the pipe, then heard a small pop and a whoosh of water after that. My husband checked the drainpipe farther down the line (towards the bottom of our property) to see if water was flowing, and it was, so we know we didn't create a bigger problem of a burst pipe with the pressure bladder.
    – Sharon
    Oct 27, 2022 at 17:31
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    @Sharon So the pressure bladder worked is what I am reading? If so, you can give me a check mark on my answer. As that informs me that my solution actually worked. I happen to catch your comment by accident. Thanks. Oct 30, 2022 at 0:01

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