I am interested to find out from you guys on how can I fix this problem.Over the last 12 months we have had super bad smelly shower drain.I am a GC and have tried so many process to solve this issue.(Enzyme treatment, removing any hair in the 2 inch cast iron trap, baking soda with vinegar etc).I have talked to my 3 different plumbers about it but it is not getting better.I have tried Enzyme treatment for 6 months and no good result! PLEASE HEEEEEEEELP!!!!!!!!

The tail piece at the shower drain could be too long causing the drain water to fall at such a speed as to wash out the trap, rendering it ineffective and not sealed from sewer gas coming into that shower room.

Thanks for your feedback SLOREN (CA).This house was built in 1976 and I have not changed any fittings or trap assembly since it was installed. We have owned this house for 25 years and it was never a problem until last year.

Is there water in the trap when you get the odors?

Paul's question about if there is water in the trap leads me to think that because it is cast iron, the trap may have a rusted out hole in the bottom of it. The only way to tell is to camera the drain to the trap. You might be able to rent a short camera cable at an equipment rental store.

Hi Paul,
there's water in the trap.

Is this a tiled shower? If yes, maybe the odor is not from the drain piping, but from the mortar bed. After treating the drain, is the smell gone for a while or is it always there?

If the drain is clean, and from what you say, it has to be. There is water in the trap up to the weir(?). Then the smell is from other than inside that drain. Check the seal of the drain to the pan. If it is leaking, you may have a lab culture under the pan.

Hi Steve
As soon as we used the shower the smell comes back. if i add any powder to kill the smell (Home depot lavender capsules)it goes away until the next day.

so, lift the chrome cover off the shower drain and stuff something into the pipe to eliminate the pipe as the source of the smell.
if the smell is coming from under the tile rather than from the drain, you will know right away.
it does seem from your description and from what you have done that the smell is coming from the pipe, which makes no sense given all you have done to correct this ?

A possible source for leaks is the tail piece of the shower drain where it is either leaded or sealed with another material. There is a rubber O-ring that is stuffed between the pipe and the SS Drain to make a proper seal. If the shower is upstairs this can be problematic and need periodic attention and could show up in the ceiling.

Hey, Patopat; I can't determine how long it's been since you first posted this issue but I was wondering if you ever determined the source of the odor.

As one person suggested, my plumber also believed the culprit to be water trapped underneath the drain pan that somehow leaked outside of the drain pipe.

However, it seems that this drain compression gasket is pretty hefty and hammered into place so I'd be surprised if water was able to leak past...

At any rate, just curious to see if you had any updates. Thanks very much in advance.


CW.