Gurgling under kitchen sink but no water running

[markjg123]

I live in a flat and can occasionally hear gurgling under kitchen sink when I've not been running any water. What might the cause be and, apart from the mild annoyance, should I be concerned?

 

[Harry Bloomfield]

What sort of flat? Might another flat owner, be running some water to their drain, which is causing some suction at yours?

 

[markjg123]

I live in a flat in a converted mill. I think all that was left were the external stone walls and slate roof. The internal is all new build. It's a strange layout and I don't fully understand it. It's over 3 levels. I have the ground floor. My neighbour had the 2nd floor. We share the first floor. My kitchen is on the first floor. I have no idea what is above it.

 

[Madrab]

If you aren't running water down the drains at that location then it'll be another neighbour that is, if too many thing are on a given waste run or if it hasn't been piped correctly then you will get suction at your trap. Trick to fixing that would be to get an anti vac trap unless you get someone in to inspect the waste/drain runs.

 

[markjg123]

If you aren't running water down the drains at that location then it'll be another neighbour that is, if too many thing are on a given waste run or if it hasn't been piped correctly then you will get suction at your trap. Trick to fixing that would be to get an anti vac trap unless you get someone in to inspect the waste/drain runs.

I'll take a photo of the sink plumbing tonight and perhaps you can advise on which bits to replace and with what parts.

 

[markjg123]

One thing I have noticed about the building is the only visible external pipework is rainwater drainpipes and gas supplies. There is no visible waste water pipework. I don't know if this is because it's a listed building or just how the conversion contractor chose to do it. From what I can tell the building was just the stone outer wall shell and slate roof. The internal structure of the 4 flats over the 3 floors looks to have been constructed using breeze block, then the internal rooms finished with studs and plasterboard. So I guess it's possible all the waste pipework is hidden and runs between the breeze block and stone shell to the several drainage points around the building. There's also a pump to move it to the main drain.

 

[markjg123]

If you aren't running water down the drains at that location then it'll be another neighbour that is, if too many thing are on a given waste run or if it hasn't been piped correctly then you will get suction at your trap. Trick to fixing that would be to get an anti vac trap unless you get someone in to inspect the waste/drain runs.

Here's the pipework under the kitchen sink.

 

[Madrab]

OK - look like an adjustable anti vac (syphon) trap will replace that.



Adding to that - they could have made all that a lot tidier - taken in higher up closer to the sink bowls and then down the back of the cupboard to give you more useable space in there, the appliance waste should also be raised up as high as possible inside that space and then down to connect to the spigot.

 

[markjg123]

All of that makes good sense. I just need to understand exactly how to do it. The simple bit seems to be replacing F with the trap you've recommended. I understand shortening A and B, and possibly C and D too, but not clear on how to direct to the back of the cupboard to create space. As for E, do you just mean raise it as much as I can at the point it connects to the spigot? I don't think I can get to the bottom of it though. It's for an integrated dishwasher that's right next to the sink cupboard.

 

[Harry Bloomfield]

Your machine drain, E, needs to loop up, just as high as possible, before dropping. Ideally, the top of the loop, should be higher, than the highest level of water, you can ever get in the sink. The idea is - if the outlet D, becomes obstructed, as E is at the moment, water plus debris in the sink, will back flow into the machine.

 

[markjg123]

Your machine drain, E, needs to loop up, just as high as possible, before dropping. Ideally, the top of the loop, should be higher, than the highest level of water, you can ever get in the sink. The idea is - if the outlet D, becomes obstructed, as E is at the moment, water plus debris in the sink, will back flow into the machine.

Something like my son's tidier configuration?

 

[Harry Bloomfield]

Something like my son's tidier configuration?

Certainly better, but the grey machine drain pipe, is still looped to low. A pipe clip, as high as possible under the draining board, would fix it.

 

[markjg123]

Certainly better, but the grey machine drain pipe, is still looped to low. A pipe clip, as high as possible under the draining board, would fix it.

OK I see what you mean. I can fix that for me and him.

 

[markjg123]

The bit of the suggested reconfiguration I'm still unsure about is how to shorten A, B and C and still be able to connect F to D.

 

[Harry Bloomfield]

The bit of the suggested reconfiguration I'm still unsure about is how to shorten A, B and C and still be able to connect F to D.

I'm not sure either

I would shorten A and B, to the minimum you can manage. Fit your new anti-syphon trap on D, leaving D unmodified, Then just replace C with a new piece of pipe, what ever length fits.

You might, by juggling the bits of pipe you have - get away without buying any new pipe.

I don't think there is much to be gained by modifying D, but doing as I suggested, with make for a neater arrangement, and better use of the space in there.