Does this boss pipe need venting

[dadthesplunge]

Can anyone help? We have a washing machine in the garage and the waste water drains outside (white pipe in picture) to an external boss pipe which also drains a downstairs toilet (never used for solid waste!). There is a bad drain smell after the washing machine empties (it is a new washing machine). My question is: Is the problem caused by the trap for the washing machine being syphoned and does this mean the boss pipe needs venting ?? Any suggestions anyone?
many thanks
John

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• dadthesplunge
• 31 Mar 2011
• 1

 

[stem]

Sewers and drains do smell, the trick is to stop the smell escaping. Is there a 'U' bend or 'trap' filled with water to prevent the drain smells escaping? It should be something like this.

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• stem
• 1 Apr 2011
• 1

Sometimes the hose can be pushed right around the bend so that it comes out on the other side of the water to reach the sewer gasses, which will then travel up the hose and back to the washing machine.

 

[dadthesplunge]

Hi Stem
thanks for the reply. Yes there is a u bend inside the garage next to the washing machine like your diagram. I can't see anything wrong with the pipe arrangement but I dont know anything about the black boss pipe in my picture, not sure if it needs to be vented like the normal outside stack which is vented near the top of the house. Can gases from the sewer get in the machine during the emptying phase of the wash cycle?

thanks

John

 

[xr4x4]

Where is the smell coming from?

If it's coming from the stack, then maybe it's the auto air admittance valve faulty.

 

[dadthesplunge]

It seems to be coming from the machine drum, the machine is only a couple of months old so I dont think there is anything in its pipework

 

[dadthesplunge]

By the way where is the autoadmittance valve?

 

[xr4x4]

It should be on the top of that black stack in your picture.

Have you got a picture of the washing machine trap?

 

[John506]

Fit a HepVo valve and you don't have to worry about any induced siphonage.

Just fits onto the white pipe in your picture close to the washing machine.

 

[dadthesplunge]

Thanks for all your help. Here is a picture of the trap near the washing machine

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• dadthesplunge
• 2 Apr 2011
• 1

 

[ironman1]

How long is the run from washing machine to stub stack (self syphonage)?.......................durgo valve (AAV) would normally only be fitted if soil stack run is in excess of 6 metres with no vent.... don't like those durgo valves.....................induced syphonage from WC could be an issue if drain run is excessive coupled with too many bends (plugging).

 

[JonB]

Dad
why cant you put the photos the right way up??

 

[ElRadgieJoof]

It should be on the top of that black stack in your picture.

Air admittance valves ( Durgo Valves ) should only be fitted
within a building to avoid the risk of them freezing.

 

[dadthesplunge]

Hi Ironman1
the pip run is about 10 feet in total, after the trap near the washing machine there are 3 bends

 

[dadthesplunge]

To all, sorry about the pictures being the wrong way! I took them in portrait mode to get all of the pipes in view but when they were uploaded the pictures were changed to landscape mode!

 

[xr4x4]

It should be on the top of that black stack in your picture.

Air admittance valves ( Durgo Valves ) should only be fitted
within a building to avoid the risk of them freezing.

Eh?

So that stack is venting open?

Back to the washing machine, do you leave the door closed when not in use?