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gmroberts 11-15-2010 09:39 AM

air bubbles from shower drain
We have a horizontal shower drain installed that looks similar to this:

The contractor who installed it failed to place a syphon in the drainage pipes which are accessible in our basement. We soon had sewer odors coming though our shower drain. Recently, we had another plumber install a syphon which corrected the odor problem.

However, the drain in our shower is now very slow. In fact, we have to turn if off after 2 min to allow the drain to catch up. I've noticed that there seems to be air bubbles coming trough the water when we first start the shower.

When the syphon was installed, the pipe that feeds into the outside sewer pipe was sealed and made air-tight. Could the air pressure in the pipes prevent water from draining fast enough?

gmicken 11-15-2010 06:43 PM

Does the sewer drain have a vent ?

gmroberts 11-16-2010 02:22 AM

The drain pipe which I believe is around 50cm goes into a larger sewer pipe. Today the plumber removed the cement seal he made around the larger pipe in a effort improve the speed of draining. It didn't help. There are still air bubbles which rise through the shower drain.

There is no separate "air" pipe attached to the water pipe.

Thanks for any advice.

Redwood 11-16-2010 08:15 AM

You need a better plumber that can actually fix your problem.
Also the terminology you are using is completely wrong and I have no idea what you are talking about other than the drain is slow and bubbles are coming out of it which could indicate a clogged drain or another problem.

gmroberts 11-16-2010 08:45 AM

Please let me clarify. The shower is on the ground floor. A "S" trap was recently installed in the basement at the point were the waste water pipe drains into a larger sewer pipe. The contractor who originally installed the shower neglected to do this resulting in sewer gases rising through the shower drain.

So now we don't have sewer gases but the drain doesn't work fast enough. The plumber came today for the third time and snaked the drain so it's not blocked. Could the trap slow the flow of waste water?

From what I've read, waste pipes should be a vented to allow for the proper flow of water? Since there are air bubbles rising through the drain this would seem to be the problem? If this is correct, the plumber I'm using has never heard of doing this.

Jimbo56 11-17-2010 04:17 AM

i am not an expert in this area but i would suggest getting a second plumber in maybe that would help you. I can only guess it is too do with the ventalation but i wouldnt be 100%, get a second opinion.

Redwood 11-17-2010 06:50 AM

S-traps are illegal. Still I don't know if your terminology is correct.

Maybe if you posted a picture it would help.

But my best guess is you need a better plumber.

gmicken 11-17-2010 07:45 PM

Not seeing the piping, its hard to say. But if I was a betting man, I would say the digbat that install a shower without a Trap, possibly has no idea about the slope needed for the water to flow. If he put the drain at the minimum slope and the new plumber installed a trap. That coud have put the pipe at a negative slope. If the shower had a 90 degree elbow and then the slope, depending on the size of the pipe, the elbow could have been 3" from the bottom of the shower. When the trap was installed it could of dropped the pipe 6" or 8" causing not enough fall. Just a thought. G

nealtw 12-16-2010 05:07 PM

You have a shower and a trap leading to the drain, Do you have a fresh air vent that goes right thru the roof anywhere close to this, you always need air behind water and if the vent is to far away the pipes will pull air thru the trap or really slow the drain.

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