This Blog Isn't In the Toilet

Three Possible Sources For The Foul Smell Coming From Your Sink

When rotten odors start coming from your sink, there are a few different things that can be causing the problem. Knowing what signs to look for can further help you narrow down where the smell is coming from, and with the help of a professional plumber, you can get rid of it in no time.

Dry P-Trap

Most drains are installed with a P-trap, a curved section of the pipe right underneath the drain. The primary function of this curve is to let water sit in it at all times; having water in this trap prevents any odors from the sewer from coming back up the pipes and into your house through the drains.

Most drains in your house will see regular use, but if you have any that are less frequently used, this could be the source of the problem. If the water evaporates from the trap, and lack of use prevents it from filling back up again, there's no longer any barrier between the pipes leading directly to your sewer and your house.

To troubleshoot this, run some water down every sink in your house. If this fixes the problem, the solution is to simply run water down your sinks every week or so. If it doesn't, there could be some corrosion or gunk in the trap itself that needs to be either cleaned out or replaced.

Clogged Drain Vent

Drain vents are another way foul smells are filtered harmlessly out of your house. On top of regulating the air pressure within your pipes, vents are also where sewer gases can escape from your pipes.

If any of your vents are clogged, those gases can end up coming out of your drains instead. One sign this could be the problem is if the smell seems to be coming from several drains that are close together, such as all the drains in one bathroom. Another sign is a slowing in drainage; if the vent is clogged, any drain pipes attached to it will slow, even if there's nothing physically blocking anything coming down the drains.

If you suspect this might be the case, call a plumber to inspect and clear out your vents.

Corroded Water Heater Rod

Water heaters are built with a metal rod on the inside of the tank, known as a sacrificial anode rod. Depending on what material this rod is made of, once it starts to corrode, you may start smelling an odor like rotten eggs.

One sign that this could be the problem is if you only notice the smell when hot water is running, and this is an indicator that the smell is coming from water coming into your house, not the drain itself.

If this rod is the problem, it likely means the rod is made of magnesium or aluminum. Luckily, this rod can be replaced without needing you to replace your entire tank. Further, having it replaced with a rod made of zinc can help prevent this from happening again.