Sewer gas escaping

[Graeme000]

Hello,
Sadly I have a foul smell escaping from the wc in my house.
I have attached a picture of the current set up.

I am about to replace the washing machine stand pipe as it looks in a poor state but is there anything else you can see that may be causing this problem? Or any suggestion what to investigate?

Thank you

 

[opps]

I am not a plumber- but what is the round cap on the top of the soil pipe? Might the smell be from there?

 

[Graeme000]

I am fairly sure it's an air admittance valve. It is sealed tight to the branch socket, I can't move it at all. From what I have read air admittance valves don't need maintenance so I'm assuming it's working as intended

 

[Deleted member 267285]

I am not a plumber- but what is the round cap on the top of the soil pipe? Might the smell be from there?

A round cap (underground coloured one at that), but yep just a drain cap. Looks like it’s been siliconed in, so @Graeme000, you could check there and the branch connecting to the floor drain.

 

[Deleted member 267285]

I am fairly sure it's an air admittance valve. It is sealed tight to the branch socket, I can't move it at all. From what I have read air admittance valves don't need maintenance so I'm assuming it's working as intended

It looks like a cap to me. Is there a vent pipe/stack anywhere on the system?

 

[Graeme000]

A round cap (underground coloured one at that), but yep just a drain cap. Looks like it’s been silicones in, so @Graeme000, you could check there and the branch connecting to the floor drain.

So it's not an air admittance valve?
Is there not meant to be a way of allowing air pressure to escape?

 

[Deleted member 267285]

So it's not an air admittance valve?
Is there not meant to be a way of allowing air pressure to escape?

No, it’s not an air admittance valve look here. This is what one should look like: AAV

 

[Graeme000]

It looks like a cap to me. Is there a vent pipe/stack anywhere on the system?

Sorry CBW we overlapped on our responses.

Can I clarify what you mean by anywhere on the system?

There are two other toilets, both have air admittance valves in the loft. Would this count?

I always thought it would have to be at each entry to the sewer pipe?

 

[Deleted member 267285]

Sorry CBW we overlapped on our responses.

Can I clarify what you mean by anywhere on the system?

There are two other toilets, both have air admittance valves in the loft. Would this count?

I always thought it would have to be at each entry to the sewer pipe?

If you live in say a Terraced house, the drains might only have one soil and vent pipe, but even then, they can be 1 in every 3 houses, but can be at the head of the drain. As long as there’s ventilation, however your 2 air admittance valves wouldn’t count for this.

 

[Graeme000]

It's a detached house, three toilets, this is the downstairs wc.
The two upstairs toilets are as I described above.

Is the current arrangement not correct?

 

[Deleted member 267285]

Is the current arrangement not correct?

Not really, it’s basic building regulations see point (d)

 

[denso13]

Is the current arrangement not correct?

Depends how far it runs to the main drainage run, probably ok.

 

[Graeme000]

Sorry folks but this is confusing things slightly so I will try and ask a couple of questions to hopefully help understand it better.

The house has been like this for 9 years since built and it hasn't been a problem.

There is no external air vent for the soil stack, there are two AAVs in the loft which are attached to the two toilets on the second floor.

This is the downstairs toilet and is as pictured, there is no air vent (other than the little gap at the top of the stand pipe for the washing machine).

From the picture and the information above is anyone able to suggest where the smell may be coming from? I am happy to replace all/any pipe to see if that fixes the problem but if it can be targeted I would happily do that first?

Thank-you

 

[ShowerWoe]

Smells can come from waste traps from sinks/baths and loos that don't have any water in them. For example due to evaporation after not being used in ages. As the loo is removed could that be the problem of the smell ?

 

[Nige F]

Look in your manhole(s) a blockage can cause smells - all running free - no smells