My kitchen sink has been draining slow for many years now. I've just put up with it thinking it was OK but now I'm tired of waiting for it to drain. It's a strange problem. When I use a normal plunger it seems like it clears a blockage because once the water flows it drains fine as long as I keep the water running. When the water stops and it settles down, the slow draining returns. If I repeat the process it works again but resets again. I've tried snaking and poured all sorts of chemicals down there to no avail.

At one point a plumber came round and spotted that the pipe leading down to the ground was inverted and was collecting water that's why the water was draining slow. So rather than paying him to sort it out then I decided to fix the problem myself. So I sorted the inverted pipe out but the problem still exists. I've also taken all the pipes apart and poured water directly down the pipe after the 'P' trap and it flows fine. With the 'P' trap still removed I run the water to see if the 'P' trap was OK and not inhibiting the draining. The water drained very fast from the sink through the 'P' trap so that wasn't the problem. When I put all the pieces back together the slow draining is back.

It makes me think there is some kind of air pressure issue or something inhibiting the water from draining properly (not sure if that's the right term, I am not a professional plumber). I don't know what else to try other than call the plumber to sort it out but I can't afford it at the moment :(. Any help is much appreciated. Thanks

My kitchen sink has been draining slow for many years now. I've just put up with it thinking it was OK but now I'm tired of waiting for it to drain. It's a strange problem. When I use a normal plunger it seems like it clears a blockage because once the water flows it drains fine as long as I keep the water running. When the water stops and it settles down, the slow draining returns. If I repeat the process it works again but resets again. I've tried snaking and poured all sorts of chemicals down there to no avail.

At one point a plumber came round and spotted that the pipe leading down to the ground was inverted and was collecting water that's why the water was draining slow. So rather than paying him to sort it out then I decided to fix the problem myself. So I sorted the inverted pipe out but the problem still exists. I've also taken all the pipes apart and poured water directly down the pipe after the 'P' trap and it flows fine. With the 'P' trap still removed I run the water to see if the 'P' trap was OK and not inhibiting the draining. The water drained very fast from the sink through the 'P' trap so that wasn't the problem. When I put all the pieces back together the slow draining is back.

It makes me think there is some kind of air pressure issue or something inhibiting the water from draining properly (not sure if that's the right term, I am not a professional plumber). I don't know what else to try other than call the plumber to sort it out but I can't afford it at the moment :(. Any help is much appreciated. Thanks

the pipe leading down to the ground
Tell me more about this pipe. Does it go from the trap down into the ground. Did the words "S" trap ever come up in conversation with the plumber? Does the sink have a little gurgle as it drains? Back to you, Tom

Hi, Thanks for replying so fast. No the plumber never mentioned any 'S' trap. He took one look under the sink and said it looks like it's that inverted pipe that is causing the problem cause the water would back with if there is no flow of water.

Anyway I've since tried more tricks and I seem to have got it working to a certain extent that I am happy to live with it. Basically it seems whoever installed the pipes originally did a real bad job. The problem was not enough fall between the pipe that run's horizontally before going into the ground (this was the original inverted pipe I mentioned). So I just readjusted this pipe by lowering closer to the ground to create more of a drop from the sink. Now it drains must faster, not perfect but without having to redo the entire piping I'm willing to settle for this. Thanks again for your comments!

Does your drainage look like this? (see image) Let me know, Tom