Unpleasant smell in 2 bathrooms

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lukef99

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Hi
I have this issue in my house where the main bathroom upstairs, and the downstairs toilet, both have a strange unpleasant smell, I'm assuming sewer-y. The en-suite is fine, although the previous owners did some dodgy renovation and behind the vanity unit is a massive hole in the wall into the cavity where I'm assuming the old toilets waste that was there went into, and it does have an odd smell coming from there but it smells different and unsure if related (problem for another day) They are in different soil stacks - the en-suite and the downstairs toilet share one, and the main bathroom is on its own. I have changed both AAVs in the loft as a precaution but no difference. All drains have been cleaned and I cannot find any evidence of any traps evaporating. It's one of those ones where the smell isn't consistent, sometimes it doesn't smell sometimes it's strong, and I cannot locate a single source of smell by sniffing various areas, it just builds up in the rooms.

One thing I have noticed in the main bathroom is when the toilet is "used", you can hear the water that is being displaced from the trap running in I'm assuming a pipe either behind a wall or under the bath - is that normal? Does that indicate there is an air leak somewhere meaning you can hear it, and is also letting the smell out with it?

Does anyone have any ideas? It seems too coincidental to have 2 bathrooms sharing the same issue, but they are on totally seperate stacks so not sure how else it can be related? I am by no means a plumber..
 
Exedon said:
Have you lifted inspection chamber lids to make sure drains are running clear?
I take it your property has no open vent for the drains?
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Hi, no I haven't, I assume this will be a manhole cover somewhere around the perimeter of my house? Do i run water/flush from every tap/toilet and ensure I see it flush through okay?
In terms of venting I just know that there are 2 soil stacks that terminate in the loft, and I have recently replaced both AAVs sat on top as a first step
 
My money would be on a blockage or dip somewhere in the drains, and when you're flushing the WC's it's causing air displacement in the system, which is forcing it's way out somewhere, probably via a trap. Hence why the smell comes and goes.

Check system for blockages, lift Manholes and get someone to flush WC's, see if it runs through without too much delay. As Nige says, an open Vent would help, should be at least one on the property regardless.
 
I can only locate 2 stacks and they both terminate in the loft with AAVs on top - there is not an externally vented one and as far as I can tell no other houses on my estate do so just all have the same layout.
 

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Any Tile/Ridge vents in the roof? Not unheard of for lazy/cowboy installers to chop off a soil vent, cap it with an AAV and proceed to use the vent through the roof for an extractor fan, rather than provide a new outlet point for the fan.
 
I am not a plumber-
Hugh Jaleak said:
My money would be on a blockage or dip somewhere in the drains, and when you're flushing the WC's it's causing air displacement in the system, which is forcing it's way out somewhere, probably via a trap. Hence why the smell comes and goes.

Check system for blockages, lift Manholes and get someone to flush WC's, see if it runs through without too much delay. As Nige says, an open Vent would help, should be at least one on the property regardless.
Click to expand...

I am not a plumber, but I have worked in houses where flushing the loo sucked the water out of the trap on the bath and let the sewer fumes to escape out of the bath.

As a test, I would pour some water back in to the bath, and the smell ceased.

I agree that I sounds like a partial blockage.
 
So I have from memory 5 (i think) black plastic flexi pipes that come down from vent tiles on the roof and hang in the loft. One of them has my en suite extractor fan attached to, the others are just hanging there for what I assumed to be general ventilation for the loft. Could I remove the AAVs and pipe the stacks over and attach to these? Is there a specific way of doing this ie can only use solid pipe work or can i just use flexi hose like an extractor fan? Assuming there is at least 1 pipe still open for general loft ventilation?
 
Certainly no harm in giving it a try even as a temporary bodge, just remove the AAV and connect the open pipe end to one of the vent tubes maybe with a scrap of tumble drier hose and tape. If it works to resolve your problem, make a decent job of it. If no change, you've not lost much
 
Are there any regulations about how it's piped to the roof tile? I understand there shouldn't be any bends in the "wet" section for obvious reasons but above this when it is purely for venting, can i just pipe it over any which way possible? Or have to be solid pipe? have to be vertical, no 90 degree bends, any of that?
 
lukef99 said:
Are there any regulations about how it's piped to the roof tile? I understand there shouldn't be any bends in the "wet" section for obvious reasons but above this when it is purely for venting, can i just pipe it over any which way possible? Or have to be solid pipe? have to be vertical, no 90 degree bends, any of that?
Click to expand...
All questions that can be dealt with later btw; first experiment to see if AAV/lack of vent causes the problem
 
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