We own a home that was constructed in the 1950s. Last year, we replaced the sink, faucet, and plumbing in our bathroom. Soon after, we noticed a rotten egg smell occasionally showing up and the sink would back up, taking around 30 seconds to drain. A plumber came out and cleaned out a significant amount of hair and grease, which fixed the drainage issue. However, now whenever we turn on the faucet, that awful rotten egg smell returns. I've read about the overflow hole, which is located at the back of the sink above the drain. Can anyone help me figure out whether the issue is with the drain or the overflow? I've already tried using enzyme cleaner overnight, but that only helped for a few days. What are my options?
6 Answers
Check your venting again, and if you're still having issues, you may need to have a plumber blast the line to the street. If you have trees nearby, their roots could be invading your pipes. Also, make sure the outflow pipe has a proper slope; older homes can sometimes settle and cause drainage issues. I've had similar issues happen at my mom's house that was built in the early 70s.
The water itself could be the problem. If you’re getting that sulfur smell, consider getting an electrically charged anode for your water heater. That can help eliminate the rotten egg odor.
Definitely look into your venting system! It might be worth installing an Oatey Sure Vent right under your cabinet. The vent should be above the drain at the bottom of the sink to work correctly.
It sounds like you might be dealing with sewer gas, which could be caused by a faulty vent or an improperly installed trap. Also, if you have one of those accordion-style flex pipes, they can trap food waste that ends up smelling bad. You might want to check those first.
Just a thought—do you have a proper p-trap? Make sure it forms a U-shape and connects horizontally to the wall, not just dropping straight down. If it’s set up incorrectly, it could let sewer gas escape if the vent isn’t working right. Try running a little water in the sink and flushing the toilet to see if it gurgles—that’s a classic sign of a blocked vent.
Have you tried using baking soda in the drain? Let it sit for about 15 minutes before running water down it. I've noticed that when I drain liquid from dry beans, the sink gets smelly until I do this!