Hole in Soil Pipe and Uncertain Soil System

[confusingpipes]

Hello,

I recently purchased a house. Immediately upon moving in I noticed a foul smell coming from my bathroom. After investigation I discovered the smell, or at least some of it, was coming from the waste end of the bath u-trap. Simple enough to fix. However whilst doing this I also investigated a leaking wc pan connector and in doing so discovered another source of sewer gas; a hole in a soil pipe connected to the toilet. See image;



I wasn't sure if this was being used as a very poor vent, meaning that there is an issue with the vent. I've now looked around my house and I'm not sure if I have a soil stack or an air admittance valve. Either way the location of what I've found (see picture) seems odd.[FONT=&quot]

As you can see its on the opposite side of the house to my bathroom which seems odd. Due to issues with a leaking wc pan connector, the hole in the pipe and other issues, I want to install a new toilet and soil pipe. However first I want to make sure my ventilation system, be it soil stack or otherwise, is working.

What next steps in investigation could I take?

Many thanks,

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Confusingpipes

 

[Dotty]

Try plugging the hole to see if water is pulled out of the pan when you flush.

 

[rocketmanbkk]

On trying to zoom in it doesn't look like an
Aav but I can't see it clearly

 

[snowhead]

I suspect that hole has been drilled to create access for a flexible rod to clear blockages.
Or to allow air out because of a partial blockage downstream.

Does the pipe from the WC drop thought the (kitchen)? below and into the ground ?
Or is it concealed in the extension sloping roof and ends up in the stack which vents through the roof?

 

[confusingpipes]

Try plugging the hole to see if water is pulled out of the pan when you flush.

Thanks, I've now done this given this given the toilet a solid five or six flushes; water draining out of the pan at normal speed. So seemingly even with the hole covered air is getting in to ensure low pressure doesn't develop.

So even though I haven't gotten to the bottom of my ventilation system it seems its working...

 

[joni os]

Bandage over hole with 2 or 3 turns of 4" wide gaffer tape, this will stop smells and allow you to assess if absence of hole effects seal in bath / basin etc. If hole not needed, a neat solution would be to temporary disconnect pan connector and slide
a slip coupler along pipe to cover hole.

 

[Captain cool]

The previous owner might of had a blockage and it could of been a plumber or the owner that decided to drill it to find out.
Onto the more pressing matter of the skids in the toilet pan... That one no doubt was the cause of the blockage.

 

[woodsy]

Suspect hole in soil is where a previous installation of a wc suite with overflow has had the overflow taken into the soil - seen it too often by diyers with the incorrect tools

 

[Masood]

Suspect hole in soil is where a previous installation of a wc suite with overflow has had the overflow taken into the soil - seen it too often by diyers with the incorrect tools

That was my thought, too. The hole looks the right size for 20mm overflow. Bet the WC/ cistern has been replaced, probably quite recently.