Ensuite waste plumbing advice...

[BlueLoo]

Hello all,

Happy new year etc.

I have an ensuite which has issues with its drains and i should really fix it properly.

It has a toilet with a 4" drain going straight from the toilet outlet to the sewers on the ground floor. This has no vents or stack. It is a straight run down.

Very close to the toilet outlet, the combined sink and shower drain (1.5") tee into the top of the 4"toilet drain.

This arrangement causes syphoning of the p traps in the sink and the shower occasionally.

To stop this, i think i really need a air vent added to the 1.5" combined drain. I am thinking of a combination ptrap-vent or tee-ing off under the sink and adding a separate vent. (One way obviously).

Am i right?

Am i missing anything?

Any suggestions for an actual valve?

Thanks.

 

[Madrab]

Pics of the connection would be of help.

TBH though a 110mm soil pipe should always be vented at some point to avoid the exact behaviour you describe or avoid self syphoning. You could get away with an antivac trap on the sink or add an AAV into the head of the 11/2"run or get a pan connector that has a vent boss and add an AAV in to that.

 

[BlueLoo]

Thanks for the reply @Madrab

I can't take pictures, the plumbing is buried under tiled flooring as installed when they built the house. (I thought correctly, but i am constantly being proved wrong..)

However, it looks something like this but without the AAV


I'll look at the options you said.

The pan connection with a vent sounds like a good solution