We are experiencing a strong septic odor from our bathroom sink. This is the second time this month it has happened, it also appears to happen when the weather is cold?
Any ideas what may be causing this problem,and any solutions to offer..

Thank you.

The j trap below the sink should prevent any gases from entering the room but I'm assuming the trap has water in it. You may have mold or mildew growing inside the overflow chamber of the sink. Usually the over flow is a vent-like opening nearest you when you stand at the sink. The vent allows overflow water to drain down below the stopper but above the j trap. You could try a 1:3 ratio of fresh bleach and water, poured into the vent. It will not fill up and allow soaking unless you are willing to disconnect the trap and temporarily plug it with a rag.

Remove the stopper from your sink. Look down in the drain and you will see a rod about 6" down. Hair hangs up and fermemts on that rod. Fish it out,(ugh!) The reason you smell it at the overflow is that when you drain some of the smell is forced back out the overflow. Now pour a quart of bleach down the drain and let it set overnight. Next morning,(and this is important)flush it out with a pan of boiling water If you can't pull the stopper out then your stopper has a opening at the base that the rod goes through so that it can't be pulled out. To defeat this and pull the stopper look under the sink and follow the pop up lever down to the rod. You will see a knurled nut. Now push the pop up knob so the stopper is in the up position. While holding the stopper in one hand, slowly back the nut out until it's clear,(You may need to free it with a pair of pliers) Careful! You don't want to pull it all the way out. Now, GENTLY pull back on the rod while pulling upwards on the stopper. As soon as the stopper clears turn the nut back in hand tight or tight enough to hold the plunger rod up. From here on in you will let the stopper ride on top of the rod instead of tying it down. Now take a bent coathanger and fish out any hair that may have hung up on the rod or the trap. After you have cleared out any hair or trash, just drop the stopper back in the drain. When I install a bathroom sink I never tie down the stopper so that the owner can check the drain without the expense of a service call. That should take care of that smelly sink. More questions? I'm as close as a click. Good luck TOM

Hi, I own and maintain rental property in a college town and you would not believe how much experience I have with this sort of thing. Sinks are twice as yucky as toilets. I think it is the soap skum which breaks down hair and other things left in the drain.

First, is the sink in at least periodic use? Drains have a "P" trap in them to keep sewer gas from coming out. If they sit around for months between uses, the water in the p will evaporate and let the gasses out. This is usually only a prioblem in floor drains and laundry sinks - although you might get this problem if your drain under the sink has a leak whoch could leak the water out of you p.

Second, is it draining properly? Many times slow moving drains develop a smell - especially when people put draino in them - yuck!

Third, whether it is draining slowly or not, your most likely source of odor is hair and crud built up in the pipe and being dissolved by soap residue. Take out the drain stopper. If it is the kind which works by a plunger on the faucet, you probably will need to unscrew a nut on the back of the drain and remove the linkage before you can pull up the stopper. Now, I bet you can see a bunch of stuff in the drain. Fish it all out (a bent wire my help if it is far down) and rinse well. If it is clogged, use a plunger -you will need to block off the sink's overflow with a wet wash rag.

If the stuff that you get out of the drain dosen't gross you out, you have a stronger stomach than me! Good luck.