Bad Smells

[1968stevec]

Hi

I'm getting really bad smells in my en-suite, mostly originating from the sink. The arrangement is as attached

layout

• 1968stevec
• 5 Nov 2008
• 1

The AAV is boxed in alongside the cistern in the en-suite and the stack in the main bathroom vents to air through the roof.

I'm running out of ideas how to solve this but I'm considering the following:

1. Extend the stack up into the attic and cap with a new AAV

2. Extend the stack right up through the roof and vent to air (I really don't fancy doing this if possible as I don't know how to seal the pipe through the roof, let alone access up on the roof)

3. Install a HepV0 vertically below the sink trap (I've tried a bottle trap with an air valve but this didn't help)

4. Install a HepV0 horizontally before the stack on the shower/sink branch (i've tried a flap/surge valve on here and it just stopped the shower draining after a while as it became clogged with hair. The gradient on this drain is quite flat with no scope to steepen)

5. Add a branch vent pipe running uphill from the sink waste pipe to the stack.

6. Drill holes in the manhole cover outside


Any ideas on which if any of these I should try (preferably not the second one!).

The sewers outside are all gravity draining and are clear. I had Wessex Water out to check this. We're at the end of the drain line and as far as I can tell there's no venting on the sewer other than the vented stack in our bathroom.

Any advice would be appreciated.

Cheers

Steve

 

[seco services]

is the basin trap being pulled when you flush the toilet etc ?
check if its full of water

 

[1968stevec]

No, it doesn't seem to be. It usually occurs when running the sink, even if just running for a few seconds. Also happens when shower runs but generally smell is coming out of sink not shower. ocassionally it does come back up through the shower. Flushing the toilet doesn't seem to create the same problem. very ocassionaly when its really bad, the smell also comes back into the downstairs lav, again from the sink.

 

[seco services]

when running the shower etc the sink trap is still full of water ?

 

[John506]

If the traps aren't pulling and they are staying full of water,

Go for the cheap option first, install a HepVO valve along the pipe run after the shower and basin.

 

[John506]

May be useful found in another post.

The smell is coming from the accumulated muck inside the overflow and waste. Over the years you get soap scum collecting along with fats, hair, skin cells and other bodily wastes and this forms an nice warm damp place for bacteria to grow. Bacteria really are clever tenacious little chaps, believe me.

If you can't find a chemical way of cleaning it all out, perhaps a foam, I'd get a plumber to strip the lot down, give it all a good cleaning out and remake with new wastes. Then take care to give it all a good clean out with bleach or similar every couple of weeks as part of the household routine.

Bathroom scum removing sprays are pretty effective but with a heavy deposit you'll need mechanical action as well.

 

[1968stevec]

I guess if there's a smell coming out of the sink the water in the trap must be being pulled. Either that or there's a big release of gas in a bubble rising through the trap. I'm not sure how I'd distinguish between the two.

It's definitely not coming from muck in the pipes. I've had the waste apart often enough and changed it and the shower trap for new and cleaned the pipework. I'm certain its a build up and release of gas form further down the sewer. The smell isn't always there even when I've got the pipework dismantled. It tends to come back every couple of weeks and release in overpowering amounts for a few days each time the sink (and sometimes shower) are used.

I wish it were as easy as just cleaning the pipes!

 

[seco services]

is the aav working correctly ?

 

[1968stevec]

How can I tell? I've had a feel around it and the disk under the lip does seem to move up and down freely with no suggestion that its jamming.

 

[1968stevec]

If I put a HepV0 valve aong the run after the shower and basin, will it not just clog up and impede the flow given that this pipe runs quite flat? I have tried a non return valve after the shower but this stopped the shwoer draining after a while as it clogged.