F
flyjat76
I hope someone can help me as this is driving me nuts...! I moved into a newbuild house a year ago & for the last few months have been experiencing a weird sewer gas smell. The developer's plumbing contractors are being a little defensive over it (probably because there have been numerous other plumbing issues here, mainly through shoddy workmanship) hence I thought I'd try here. Google searches etc haven't helped, & I don't trust the plumbing contractors to solve this.
Very basically, it's a 3 storey townhouse, with 1 main bathroom, 2 ensuite shower rooms & 1 downstairs WC. Each toilet is the same - 'boxed in' with a wall mounted flush-plate that can be removed to access the cistern inside the boxing.
The problem we have is that occasionally, when the top floor ensuite is flushed, within a couple of minutes the entire ground floor smells of sewer gas. Subsequent flushes are OK. Having done a little diagnosis, the smell appears to be coming from the cupboard under the stairs (ie. not another toilet - the adjacent WC room is odour-free).
Digging a little deeper, I removed the upper ensuite flush-plate & noticed that on EVERY flush, after about 30 secs, a sewer gas smell appeared from the space behind the boxing/wall, although sometimes only faintly. This toilet is directly above another ensuite on the 1st floor, & on removing that flush-plate, the smell was there too, albeit only faintly. These 2 ensuites seem to be connected to the same soil pipe that runs down through the living room. So the problem may not be as occasional as I first thought - just differing levels of severity.
Continuing my experimentation, I removed the remaining 2 flush-plates (main bathroom on 1st floor & groundfloor WC) but the smell never appeared there, despite flushing all the toilets in the house. The other 2 toilets are not vertically 'in line' with the ensuite ones.
The understairs cupboard is 'open' to the rest of the internal walls of the house, & in fact is on the same side of the house as the problem ensuites, ie. the wall inside the cupboard is the same one that both ensuite toilets back on to.
It was suggested by the developer/plumbers that a faulty air admittance valve (aav) might be to blame, but they weren't sure if one was fitted. They have agreed to look at the plans for the house but that was 3 weeks ago. In the interim, I have contacted the NHBC who have also looked at the plans & told me that the soil pipe vents to atmosphere through a roof tile vent, so an aav would not be required.
Hence I'm a little baffled. An aav inside a wall or roof space would seem to explain it (with gases escaping & circulating within the walls) but it seems that one is not fitted. If there were a leak, then I assume that the smell would be around all the time, plus I would see water damage etc. Dry traps aren't to blame, as the smell doesn't come from any toilet/sink/shower but instead the internal walls. Admittedly the upper ensuite is not used very much, but recently we have ensured that it is & the problem continues.
So if anybody has any ideas I would be very grateful to hear them!
Many thanks in advance.
Very basically, it's a 3 storey townhouse, with 1 main bathroom, 2 ensuite shower rooms & 1 downstairs WC. Each toilet is the same - 'boxed in' with a wall mounted flush-plate that can be removed to access the cistern inside the boxing.
The problem we have is that occasionally, when the top floor ensuite is flushed, within a couple of minutes the entire ground floor smells of sewer gas. Subsequent flushes are OK. Having done a little diagnosis, the smell appears to be coming from the cupboard under the stairs (ie. not another toilet - the adjacent WC room is odour-free).
Digging a little deeper, I removed the upper ensuite flush-plate & noticed that on EVERY flush, after about 30 secs, a sewer gas smell appeared from the space behind the boxing/wall, although sometimes only faintly. This toilet is directly above another ensuite on the 1st floor, & on removing that flush-plate, the smell was there too, albeit only faintly. These 2 ensuites seem to be connected to the same soil pipe that runs down through the living room. So the problem may not be as occasional as I first thought - just differing levels of severity.
Continuing my experimentation, I removed the remaining 2 flush-plates (main bathroom on 1st floor & groundfloor WC) but the smell never appeared there, despite flushing all the toilets in the house. The other 2 toilets are not vertically 'in line' with the ensuite ones.
The understairs cupboard is 'open' to the rest of the internal walls of the house, & in fact is on the same side of the house as the problem ensuites, ie. the wall inside the cupboard is the same one that both ensuite toilets back on to.
It was suggested by the developer/plumbers that a faulty air admittance valve (aav) might be to blame, but they weren't sure if one was fitted. They have agreed to look at the plans for the house but that was 3 weeks ago. In the interim, I have contacted the NHBC who have also looked at the plans & told me that the soil pipe vents to atmosphere through a roof tile vent, so an aav would not be required.
Hence I'm a little baffled. An aav inside a wall or roof space would seem to explain it (with gases escaping & circulating within the walls) but it seems that one is not fitted. If there were a leak, then I assume that the smell would be around all the time, plus I would see water damage etc. Dry traps aren't to blame, as the smell doesn't come from any toilet/sink/shower but instead the internal walls. Admittedly the upper ensuite is not used very much, but recently we have ensured that it is & the problem continues.
So if anybody has any ideas I would be very grateful to hear them!
Many thanks in advance.
