How to solve gurgling sink after fitting washing machine drain

[pstunt]

Having recently connected up our washing machine to the connector on the sink trap ( See picture ) we are experiencing very loud gurgling noises each time the machine drains. I only have previous experience of standing pipes for the washing machine and I was looking for ideas on how to solve this.

 

Should I use an air admittance valve ? Where exactly would that go ? I am guessing it would be on the downward bend towards the back of the  wall in the picture but a few inches above the height of the washing machine drain connector ?

 

I am trying to focus on solutions and not the fact that when I asked my builder I got the answer of " they all do that "

[markc]

Not ideal but if you put the T in after the trap you shouldn’t get any back noise, odours won’t get back through the washing machine so no problem there

[pstunt]

Thanks for the response. Is this what you mean ? I have sketched in red in the picture.

 

If this is not ideal what would be ?

[MJNewton]

3 hours ago, markc said:

Not ideal but if you put the T in after the trap you shouldn’t get any back noise, odours won’t get back through the washing machine so no problem there

 

Are you sure? Isn't the gurgling a consequence of syphoning caused by the large volume of water running through the pipes and sucking air behind it through trap? If so, I'd expect an air admittance valve after the trap (may have to be built in the trap if there's limited space) to resolve it as it'd provide a source of air to reduce the vacuum. 

Edited July 18, 2023 by MJNewton

[Marvin]

https://www.whitegoodshelp.co.uk/smells-caused-plumbing-faults/

[markc]

On 18/07/2023 at 14:47, pstunt said:

Thanks for the response. Is this what you mean ? I have sketched in red in the picture.

 

If this is not ideal what would be ?

Yes, that’s what I would try, I don’t think it’s air being pulled in but just turbulence noise as the washing machine dumps  water and air into the trap

[pstunt]

16 minutes ago, markc said:

Yes, that’s what I would try, I don’t think it’s air being pulled in but just turbulence noise as the washing machine dumps  water and air into the trap

Thanks. My builder is of the same opinion ie Turbulence noise. He is says he is happy to put a stand pipe in, if that's what I want. I tried to politely explain that it's not about want but more a desire to reduce the excessively loud gurgling. As I type this I feel like I am being that moaning client but it really is that loud.

[MJNewton]

Is the noise during draining or after? I think that will likely indicate whether it's a turbulence/waterfall issue or syphoning. I'd normally associate 'gurgling' with the latter but it's just a word. 

Edited July 19, 2023 by MJNewton

[pstunt]

1 hour ago, MJNewton said:

Is the noise during draining or after? I think that will likely indicate whether it's a turbulence/waterfall issue or syphoning. I'd normally associate 'gurgling' with the latter but it's just a word. 

A good question. I will have to wait for the next load to be on and listen to make sure.

[pstunt]

22 hours ago, MJNewton said:

Is the noise during draining or after? I think that will likely indicate whether it's a turbulence/waterfall issue or syphoning. I'd normally associate 'gurgling' with the latter but it's just a word. 

Having listened to the noise several times I am uncertain what the answer is. It gurgles in sequence to when the machine is draining / pumping. I know this doesn't help much.

[MJNewton]

It is usually quite obvious if it is happening afterwards (and only afterwards) as there's usually a small but noticeable pause between finishing draining and the plug of water making its way through the pipework and creating the vacuum behind it. 

Edited July 20, 2023 by MJNewton