Smells from drain in shower

[allanmartin]

Dear All,

Another issue in my endless saga of drain smells which seems to be due to idiots who have plumbed this house.

History
There is a small shower room in our house with a sink and a shower (yup, no toilet even though it was be very practical and simple to do, but that is another story). There has always been a smell in the shower room which gets worse when its hotter. Last week I took a good sniff about and it is definatly coming from the shower drain. I filled the sink, and then let the water out and put my hand over the shower drain. I could feel air running past my fingers, and could hear what sounded like free flowing water from the sink.

There is a steep drop in the drains so just thought that I needed to install an air admittance valve to stop the shower trap being sucked dry, which I have done however the problem still exists. The smell and also air running past my fingers when I test with the sink.

COULD IT BE THAT THESE IDIOTS HAVE NOT INSTALLED A TRAP IN THE SHOWER? I have attached photos, as perhaps the drain (which I sort of disassemble) when looking in it forms a trap. But I just can't see it.

Before I start to remove tiles to take a look under the shower, I though I would touch base with DIYNOT.

Thanks every and anyone

Al

 

[45yearsagasman]

When you run water in the shower, can you see water in the drain after turning off the shower? If you can then you have trap. Your pictures would appear to show a trap has been fitted.

 

[SimonH2]

Does the white bit in the third picture have a closed bottom - ie it forms a cup ?
Does the wide bit at the top of the black tube in the second picture seal to the top of the white bit in the third and/or to the bit that stays in the hole ?

AFAICS, if the answer to either is no then it isn't forming a trap.

I think I see how this is supposed to work. The water flows through the gap between the cap and the black tube, down the middle of the black tube, up outside the black tube inside the white cup, and then through the gaps in the white cup to the drain. If that black tube isn't sealed on it's outside between it and the shower tray, then smells will get through the gap.

If it was a suction problem, then I'd expect to hear it glugging as air was drawn through it.

 

[allanmartin]

Yes, you are right... it seems to make its own trap. However I see that there is a rubber seal missing from this one, so that probably does not help it create a firm seal.

Thanks very much everyone....

Al