Hello,

We have a house that was built in 2004 and in the past few months I have noticed this really bad smell coming from my drains in the master bath sinks. We have a double sink in this bathroom and notice it coming more from one than the other... any idea on what this could be and what needs to be done? In case you need to know this is a modified 2 story with a basement and this located on the upper level. The bathroom on the main level has no smells. At this point the basement is unfinished. Also this is city sewage

Thanks in advance

Look underneath the sink at the drain pipe. Is there a p-trap on it? It should be a U-bend that looks like it's built to hold a small amount of water. This small amount of water keeps sewer gas from being able to come up the drains and into your house.

If you do have a p-trap, try pouring some boiling water down the sink. A whole kettle full. See if that gets rid of the smell. Sometimes the gunk on the inside of a drain can start to smell. My mom would always pour boiling water down the kitchen drain every few months or so.

If neither of these things work, you may have a venting problem. The main stack in a house will go from the basement all the way up and through the roof. When water runs down the drain, air will get sucked in the top of the vent. If the vent is blocked, the same suction will occur, and it can suck the water right out of a p-trap. Others on this forum probably have better suggestions than me to check if this is your problem.

Cheers

dmatos gave you some good advice. Let me add to it. Most bad smells in tubs, showers and lavatories come from rotting hair mixed with grease from the soap. Pull the stopper free in the lav with the odor. ( If it won't come free click on back and I'll instruct you how to free it.) Shine a light down the drain. About 8" down you'll see a little rod sticking out. Fish out any hair that may be hung up on it. Now, before you go to bed pour 1/2 gallon of bleach down the drain and let it work overnight. Next morning flush the entire mess out with boiling water as damtos suggected. Smell all gone now?
Regards, Tom

Thank you both for your responses. Tonight I am going to try the boiling water. Although I did forget to mention I don't notice the smell until I turn on the water... not sure if that makes any difference.

Check the drain for rotting hair and then do the bleach tonight and the boiling water in the morning. Good luck, tom

This is so true. This weekend, I took apart my bathroom sink so I could paint the wall behind it. I got to taking the pipes apart and my lord it was so ugly to see all the crud that forms inside these pipes.
It was like a grease type. I ended up disconnecting all the pipes at the joints so I could clean these out before I put that back on.
But, anyway, my point is, yes it would be a great idea to pour bleach and then to flush with boiling water every so often.