Connecting washing machine

[LaChab]

Hi,

 

I'm trying to get my head round how to connect the washing machine (and TD, DW).

 

I wondered if anyone has used one of these, or similar.

 

 

 

 

 

https://www.amazon.co.uk/Mounted-Siphon-Washing-Machine-Chrome/dp/B00D6FCQO4/ref=asc_df_B00D6FCQO4?mcid=10ef8fd756793f09b624b4235a47ccce&tag=googshopuk-21&linkCode=df0&hvadid=696352102719&hvpos=&hvnetw=g&hvrand=10560092967412209591&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=20339&hvtargid=pla-422507636596&psc=1&hvocijid=10560092967412209591-B00D6FCQO4-&hvexpln=0&gad_source=1

 

 

I think it might fit in the kickspace next to the appliance, along with the cold feed and 13a socket, which would be quite neat.

 

BUT I'm worried about not using a conventional standpipe waste.

And I can't understand where a standpipe would go, as the void in the back of diy kitchens is only 42mm, and I'd rather not remove the back of the unit.

 

Advice badly needed!

[Nickfromwales]

 

 

Install the upstand inside the unit, fixed to the back or side panel  Needs to all be accessible imo.

[LaChab]

Thanks @Nickfromwales Quite agree about accessibility, that's partly why I'm dubious about using the void.

 

Would like to avoid cluttering up the cupboard / drawer unit if possible.

 

What do you think about using one of those nozzles you referred to in that topic with a HepVo. Would that seem better than the Amazon thing? That would go under the kickspace.....

[Nickfromwales]

5 hours ago, LaChab said:

Thanks @Nickfromwales Quite agree about accessibility, that's partly why I'm dubious about using the void.

 

Would like to avoid cluttering up the cupboard / drawer unit if possible.

 

What do you think about using one of those nozzles you referred to in that topic with a HepVo. Would that seem better than the Amazon thing? That would go under the kickspace.....

Hep trap will be ok, but would be my second choice tbh.

[John Carroll]

Dom't know how far away your W/machine is from any sink but I have my Dish washer drain hose connected as shown below, the hose can be seen next to that yellow container on the right,  the other waste discharge nozzle is blanked.

Edited June 17 by John Carroll

[Nickfromwales]

15 minutes ago, John Carroll said:

Dom't know how far away your W/machine is from any sink but I have my Dish washer drain hose connected as shown below, the hose can be seen next to that yellow container on the right,  the other waste discharge nozzle is blanked.

That's a combination trap, which has the issue of the dreaded 'gurgling' when the appliance is pumping out. The ideal situation is, where the discharging water is the other side of the trapped water, so it is inaudible to the room.

[LaChab]

@Nickfromwales Thanks, advice appreciated. @John Carroll Thanks for the suggestion. Those combined things do look interesting, and looking at  Screwfix etc very widely used I think. Unfortunately no sink nearby, and also I'm going to fit connections for 3 appliances.

[Nickfromwales]

1 hour ago, LaChab said:

Those combined things do look interesting, and looking at  Screwfix etc very widely used I think.

You hear the water discharging with those, so I never use them nowadays.... Not so bad if they're in a utility room with the door closed, but horrible if it's an adjoining or open-plan kitchen / dining / living space afaic.

[Super_Paulie]

11 minutes ago, Nickfromwales said:

You hear the water discharging with those, so I never use them nowadays.... Not so bad if they're in a utility room with the door closed, but horrible if it's an adjoining or open-plan kitchen / dining / living space afaic.

do you have any images of how you do it Nick, any that you are proud of showing off? kitchen arrives this week so i need to plumb up and i was going to use a combination trap but if i can avoid it I will do. 

[Dreadnaught]

Good point about the audible gurgling noise with a combined trap.

 

However, one advantage of a combined trap is the washing-machine liquid keeps the sink trap nice and clean. Sink traps are especially prone to drain-gunk build-up over long periods.

 

If the gurgling can be tolerated in, say a closed-door utility room, I wonder if this benefit outweighs the downside?

[Nickfromwales]

Very little gunk goes down an utility trap / sink tbh, so the issue is largely from food waste from the kitchen sink.

 

A decent bottle trap will allow regular maintenance, if so ever necessary, which means I would say "no" to the benefit/downside squire.  

 

I have lived here for 19 years and have cleaned my kitchen sink trap out prob less than 3 times, and that's probably because of lollipop sticks not gunk/stink related issues.

 

"People. stand united in the fight against gurgling traps!!!".

[Super_Paulie]

On 19/06/2025 at 00:38, Nickfromwales said:

Very little gunk goes down an utility trap / sink tbh, so the issue is largely from food waste from the kitchen sink.

 

A decent bottle trap will allow regular maintenance, if so ever necessary, which means I would say "no" to the benefit/downside squire.  

 

I have lived here for 19 years and have cleaned my kitchen sink trap out prob less than 3 times, and that's probably because of lollipop sticks not gunk/stink related issues.

 

"People. stand united in the fight against gurgling traps!!!".

Are you saying a bottle trap under the kitchen sink, with I guess a spigot before it for the dishwasher/washing machine? I'll be plumbing up this week and I will indeed stand united if I can.

 

I'm partial to a nice but of pipe action, so I'm hoping to not do a lash up.

[Nickfromwales]

45 minutes ago, Super_Paulie said:

Are you saying a bottle trap under the kitchen sink, with I guess a spigot before it for the dishwasher/washing machine? I'll be plumbing up this week and I will indeed stand united if I can.

 

I'm partial to a nice but of pipe action, so I'm hoping to not do a lash up.

Yes. I don't fit (or avoid with a passion) the multi-component dual trap combination nonsense that a lot of mid range kitchen sink suppliers offer up. Instead, that all goes in the skip and I just fit 1x or 2x McAlpine bottle traps and end of subject. Bombproof.

 

The pipework downstream of the traps gets a T cut in down as low as is practicable, with a 50mm spur of pipe in it and then the WM upstand connects to that.

[S2D2]

57 minutes ago, Nickfromwales said:

Yes. I don't fit (or avoid with a passion) the multi-component dual trap combination nonsense that a lot of mid range kitchen sink suppliers offer up. Instead, that all goes in the skip and I just fit 1x or 2x McAlpine bottle traps and end of subject. Bombproof.

 

The pipework downstream of the traps gets a T cut in down as low as is practicable, with a 50mm spur of pipe in it and then the WM upstand connects to that.

Can the straight nozzle on the upstand you mentioned in the linked thread cause issues with the trap as it seems to be eliminating that source of air intake or is there a distance to the T where that's no longer a consideration? Or do the bottle traps have their own?

 

I fitted an anti-syphon u bend to and existing combination trap and it eliminated most, but not all, of the noise. I think even that was a recommendation of yours so thanks for the ongoing input!

[Super_Paulie]

2 hours ago, Nickfromwales said:

Yes. I don't fit (or avoid with a passion) the multi-component dual trap combination nonsense that a lot of mid range kitchen sink suppliers offer up. Instead, that all goes in the skip and I just fit 1x or 2x McAlpine bottle traps and end of subject. Bombproof.

 

The pipework downstream of the traps gets a T cut in down as low as is practicable, with a 50mm spur of pipe in it and then the WM upstand connects to that.

 

In my instance it's a dishwasher. I have a waste coming out directly from the wall so I have effectively got a straight pipe coming into the unit in the rear, back to front. Is the attached very crude image what you would suggest @Nickfromwales, with joining pipes obviously.

 

Instead of the spigot I could make an upstand I guess but I wouldn't need that additional trap would I?

Edit. Thinking about it this would syphon all the water from the trap wouldn't it as there is no air admittance.

Edited June 23 by Super_Paulie

[Nickfromwales]

58 minutes ago, S2D2 said:

Can the straight nozzle on the upstand you mentioned in the linked thread cause issues with the trap as it seems to be eliminating that source of air intake or is there a distance to the T where that's no longer a consideration? Or do the bottle traps have their own?

 

I fitted an anti-syphon u bend to and existing combination trap and it eliminated most, but not all, of the noise. I think even that was a recommendation of yours so thanks for the ongoing input!

Traps do not create a source of air intake, an air admittance valve (AAV) does that  

 

A trap captures water to use to separate the stinky air from the foul pipework from the room air; you don't want stench from the stench pipe.

 

Air admittance is required when falling water drops like 8' for a storey of a house, at 110mm, but absolutely zero requirement for that at a WM upstand. For eg, if you have a bungalow and the invert (the distance discharged water falls from output to horizontal) is <1300mm then even for a flushing WC there is no requirement for air admittance.

 

For this instance the water dropping 600-700mm max from the upstand will never attract a vacuum so will never need any air admittance, so the focus here should be on reducing or eliminating the noise from the water entering the upstand, and DEFO to avoid the horrid gurgling water noise created by a combination sink water arrangement.

 

It's 2025 folks......there's a better way.

[Nickfromwales]

6 minutes ago, Super_Paulie said:

 

In my instance it's a dishwasher. I have a waste coming out directly from the wall so I have effectively got a straight pipe coming into the unit in the rear, back to front. Is the attached very crude image what you would suggest @Nickfromwales, with joining pipes obviously.

 

Instead of the spigot I could make an upstand I guess but I wouldn't need that additional trap would I?

Edit. Thinking about it this would syphon all the water from the trap wouldn't it as there is no air admittance.

[Nickfromwales]

The principal issue is having the appliance connect downstream of the sink trap.

 

Just buy a regular 40mm compression T and insert the bit I linked to, on the horizontal pipework, immediately off the sink trap.

 

Use the appliance hose to create your trap, as without the fall and a pipe at the bottom of the cabinet you cannot get the upstand / trap in this picture. 

 

Possibly use a waterless HepVo trap between the T and the adaptor, but something needs to stop back flow of stench from a soil stack into the appliance; if this pipework is open-ended and terminates at an external gulley then there is no 'stench' to speak of, so just the draught to deal with then.

[Super_Paulie]

5 minutes ago, Nickfromwales said:

Interesting. So it's a separate trap basically. I'll see if I can fit that in, it's just a 600 unit with the exit far left maybe 300 up, sink dead center. Sounds like I need to play with my pipe tomorrow.

[Nickfromwales]

21 minutes ago, Super_Paulie said:

Thinking about it this would syphon all the water from the trap wouldn't it as there is no air admittance.

No. Not at all.

[Nickfromwales]

Just now, Super_Paulie said:

Sounds like I need to play with my pipe tomorrow.

@Pocster one for you laddo  

[Super_Paulie]

So would this suffice? Id be happier if I didn't need that upstand under there, more room in the cupboard for my dangerous chemicals. However I could do it if I were to sacrifice the shelf.

[Nickfromwales]

3 minutes ago, Super_Paulie said:

So would this suffice? Id be happier if I didn't need that upstand under there, more room in the cupboard for my dangerous chemicals. However I could do it if I were to sacrifice the shelf.

Ok. When you say would this suffice, the problem is what is going where here? 

 

The adaptor you show is supposed to go on top of the trap and connect to the waste outlet of the sink, hence you will get "the gurgle".

[Nickfromwales]

19 minutes ago, Super_Paulie said:

it's just a 600 unit with the exit far left maybe 300 up

So, where the pipe enters the unit you have your T, and then carry on up to the sink bottle trap.

 

You use the other branch of the T to connect a WM upstand to, ensuring it is to the side of the bowl of the sink and ends as high up as is possible.

[Nickfromwales]

4 minutes ago, Nickfromwales said:

Ok. When you say would this suffice, the problem is what is going where here? 

 

The adaptor you show is supposed to go on top of the trap and connect to the waste outlet of the sink, hence you will get "the gurgle".

At this point you'd just stick with a single unit, a "combination trap".