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Hey everyone, I'm new to the forums and have an issues with my toilet. My bathroom is without any windows, so it's quite obvious when there's any smells coming from the sewer.

Behind the toilet (specifically where the waste pipe joins to the unit), there's a potent sewage smell coming through. It's definitely not from the basin or bath. The building is old (1800s), so from what I understand, the waste pipes are not outside.

Does anyone have suggestions on what's causing this, and what the solution is? Thanks in advance!
 
If your house is 1800s, it is quite possible that it was built without an indoor toilet, so it may be reasonable to assume that the plumbing was a later addition, so age is not especially relevant. In any case, indoor waste stacks were common until recently (and I'm not sure you can't still quite legally still fit them).

Assuming the wall is solid brick, the most likely cause is an imperfect seal between the pipework and the WC pan, or damage of the pipework itself. This means that foul air from the sewer can escape into the room, particularly likely if there is an extract fan. This is the most likely cause and should be eliminated from the equation before further investigation in my opinion.

Any photos?
 
If your house is 1800s, it is quite possible that it was built without an indoor toilet, so it may be reasonable to assume that the plumbing was a later addition, so age is not especially relevant. In any case, indoor waste stacks were common until recently (and I'm not sure you can't still quite legally still fit them).

Assuming the wall is solid brick, the most likely cause is an imperfect seal between the pipework and the WC pan, or damage of the pipework itself. This means that foul air from the sewer can escape into the room, particularly likely if there is an extract fan. This is the most likely cause and should be eliminated from the equation before further investigation in my opinion.

Any photos?

My bad for not mentioning, but it's an apartment block (built in the 1800s as a warehouse, but converted in the 1980s/90s.

If you're suggesting that it's a faulty seal between the pipework and the WC pan, would that require a full change in piping? At the moment, I've stuck a bit of silicone around, but I'm not sure that it will really solve the problem. Pictures attached of behind the toilet.

IMG_6037.JPG
IMG_0084.JPG
 
Where does the other end of the overflow pipe terminate? You can get smells coming through that.
What JC means is that if the overflow pipe is connected into the stack (via a saddle boss connector, but I've seen one just poked through a hole in the side of the stack) then there is now an opening from the foul air in the stack into the cistern via the overflow pipe.
Is the smell coming up the overflow pipe?

If so, may be worth pouring a pint of water down the overflow in case there is a trap on the pipework to the soil pipe but the trap has dried out.
 
What JC means is that if the overflow pipe is connected into the stack (via a saddle boss connector, but I've seen one just poked through a hole in the side of the stack) then there is now an opening from the foul air in the stack into the cistern via the overflow pipe.
Is the smell coming up the overflow pipe?

If so, may be worth pouring a pint of water down the overflow in case there is a trap on the pipework to the soil pipe but the trap has dried out.

Ah, that makes a lot of sense now. I poured some water down there. From the sounds of it, the overflow pipe is indeed connected straight into the stack. That specific unit isn't used much, so I'm hopeful that this solves the problem. I'll post back if/when the sewage smell returns, although at first instance the smell really seemed to be emanating from the waste pipe behind the toilet, and not the cistern (but I hope I'm wrong!).
 
Well that's as rough as bulls lugs. Prob a split in the flexi pan connector. The flex part doesn't look right
 
Be difficult to sort that pan connector out neatly and properly given angle of 110mm poking out from tiles and relative distances. So sticking a rag in the top of the overflow in the cistern and seeing if the smell stops would be a good first move.

If it does, don't just leave it like that, it's there to stop flooding should your inlet valve fail. Ask a plumber to check if your syphon/drop valve overflows internally and if not to replace it with one that does and cap off the overflow.
 
Just an update: the smell is definitely still lingering. More prevalent when the toilet hasn't been used. I think it's time to get the pan connection changed. Could anyone give a ballpark figure for what I'll have to pay the plumber?
 
I doubt very much that the pan connector is leaking.
My guess is still the overflow, especially since you say it's bossed into the stack.
Cover the end of the overflow up with a little bag and a rubber band and see if the smell fades.
overflows almost never have a trap built into the pipework, it would evaporate.
Depending on what syphon/flush valve you have - you might not even need the overflow.
A pic of the inside of the cistern would help.
If needed, you can use 2 90s and a length of overflow pipe to bring it back on itself (like an upside down letter 'U' )so the opening is always underwater and stops any smells.
 
I doubt very much that the pan connector is leaking.
My guess is still the overflow, especially since you say it's bossed into the stack.
Cover the end of the overflow up with a little bag and a rubber band and see if the smell fades.
overflows almost never have a trap built into the pipework, it would evaporate.
Depending on what syphon/flush valve you have - you might not even need the overflow.
A pic of the inside of the cistern would help.
If needed, you can use 2 90s and a length of overflow pipe to bring it back on itself (like an upside down letter 'U' )so the opening is always underwater and stops any smells.

Okay right - I've blocked the overflow with a sandwich bag, wrapped it around and made it tight with an elastic band. Ill attach a picture of the cistern (before I covered the overflow). I can give any other pictures if they'd help! I'm not 100% certain that it's bossed into the stack, but it sure sounds like it is after I poured water down there.

28928381_10215863191359874_1629264878_o.jpg
 
Did you put the bag over the open pipe, lowermost component in your picture? If so, that's not going to be where the smell is coming from because that type of overflow sends water straight into the pan if the cistern fills too high. The guys were talking about an overflow pipe, usually in white plastic that would come out the side of the cistern, near the top edge and taken either to a stack, or more likely to outside in a position that will cause a nuisance (by design) if the cistern overflows.

You have an internal overflow there, unless there is another overflow pipe on the side of the cistern just out of shot.
 
Did you put the bag over the open pipe, lowermost component in your picture? If so, that's not going to be where the smell is coming from because that type of overflow sends water straight into the pan if the cistern fills too high. The guys were talking about an overflow pipe, usually in white plastic that would come out the side of the cistern, near the top edge and taken either to a stack, or more likely to outside in a position that will cause a nuisance (by design) if the cistern overflows.

You have an internal overflow there, unless there is another overflow pipe on the side of the cistern just out of shot.

You know what, it's all starting to add up now ;) when I initially poured water down there, I had to toilet lid shut, so I didn't see the water come down, although you are totally correct. I've taken the bag off now. There's no other overflow pipe. That begs the question whether it is indeed a faulty pan connection?
 
Yes, it's now pointing toward that. The concertina type pan flexi does look a bit crumpled and "off" to how it should look, it has a tight crease or fold in a couple of places and this could be concealing a split.

The only thing that puts a bit of doubt in my mind is I would expect you to have at least a small water escape on flushing but not necessarily so. Water can do strange things sometimes! I'd have a very gentle poke around the folds in the pan connector flexi. The only problem with that is if it is splitting, poking at it might make it worse but at least you'd know.

Another option that might show a leak is to spray some soapy water all over that flexi, pull the flush and look for any evidence of foam or bubbles which would show a split. There is very little pressure involved in the flush pipe on discharge but hopefully just enough to make a few bubbles upon flushing.
 
I'm finally getting around to changing this pan connection (yes, the smell has been constant), would anyone be able to recommend a more suitable setup than this awkwardly fit Flexi pipe?
 
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