Highlights
The most dangerous cause of a rotten egg smell is a gas leak.
When you smell sulfur in the home, go outside and contact a local gas professional.
Once a pro rules out a gas leak, troubleshoot other causes like drain pipe issues.
Other causes of the rotten egg smell include sulfuric well water and broken drain pipes.
Your home is your sanctuary, and nothing ruins a sacred space more than the smell of rotten eggs. Sulfur is a uniquely atrocious odor, and one whiff will send you looking through your house for the cause. Follow this guide to learn all about the six common causes of this nose-pinching odor and tips to eliminate it once and for all.
1. Gas Leak
A gas leak is the most dangerous cause of that rotten egg smell, and it is by design. Natural gasses are typically odorless, which presents an extreme danger in the case of a leak. To solve this problem, gas companies started adding a chemical called mercaptan to give their gas supply that distinctive sulfuric odor. Without this additive, you’d have no way of knowing when you were experiencing a life-threatening gas leak.
What to Do
You need to rule out a gas leak as the cause of the smell immediately. Leave the house and call the authorities or contact a local gas leak repair specialist. These gas leaks are serious, so bring in a pro before considering any of the other options on this list. Better safe than sorry, right? Repairing a gas leak costs anywhere from $120 to $250, which is a small price to pay for your family’s safety.
2. Dry Drain Pipes
Dried-out drain pipes are another common cause of that rotten egg smell in the home. Dry drain pipes often happen with guest bathrooms or bathrooms in vacation homes that remain relatively unused. Sinks and tubs connect to something called a p-trap. This u-shaped pipe traps sewer gas and prevents it from heading into your home by creating a layer of water on the bottom of the curve. If the water evaporates, the sewer gas happily wafts into your home, creating a sulfur odor in the process.
What to Do
Often, the fix is simple. Run the water in any sinks and tubs in the impacted bathroom for ten minutes. This method allows the p-traps to build up the necessary amount of water to block that nasty sewer gas. If this doesn’t work, contact a local plumber for some advanced troubleshooting. They may recommend the installation of a dedicated sewer gas trap or the replacement of your p-trap.
3. Gassy Drywall
Most people assume that drywall is completely solid and poses no risk of creating any odors whatsoever, let alone the smell of rotten eggs. Unfortunately, that is not true, especially for homeowners who built houses or renovated their houses between the years 2001 and 2009. During those years, many contractors imported drywall from China that contained excessive amounts of sulfur. The end result? Drywall off-gassing a sulfuric odor throughout your home.
What to Do
Though contractors no longer import the offending drywall, many homes still include drywall sheets from the era. Authorities recommend homeowners check the copper coils in their refrigerators or air conditioning units, looking for tell-tale black ash on the copper coils that builds up when drywall emits consistent levels of sulfur.
Once successfully diagnosed, the only solution is to contact a local drywall contractor and replace all of the infected drywall. Check your homeowner’s policy or homeowner’s insurance plan to suss out any potential coverage to offset the costs. Otherwise, replacing drywall costs $60 to $90 per panel.
4. Well-Water Issues
According to the EPA, over 13 million American households rely on well water instead of treated water from a local municipal agency. Like sewage pipes, however, wells are susceptible to the smell of sulfur. In this case, the water itself develops the odor, thanks to a buildup of hydrogen sulfide caused by decaying vegetation in the ground. It’s not a dangerous occurrence, but it doesn’t create the most appealing drinking water.
What to Do
The nose knows. Diagnose the issue by shutting off the water in your home for six hours, filling your sink up with several inches of cold water, and taking a strong whiff. If the smell of rotten eggs hits you in the face, you’ve unmasked the culprit. For an even stronger confirmation, send a sample of your water to your local extension office by requesting a testing kit. What’s the fix? Plumbers recommend installing a carbon filter on your drinking faucets and putting in a reverse osmosis unit under your sink.
5. Sewer-Line Issues
Beyond a dried-out p-trap, many other sewage-related malfunctions result in the appearance of nasty odors. For instance, broken drain pipes allow sewer gasses to seep out and run amok throughout your home and exterior property. Clogged drain vents also lead to various plumbing odors, and so on. Your plumbing system is a finely tuned and fragile system, and any number of issues lead to unwanted smells.
What to Do
Troubleshoot on your own by running water throughout your home, looking out for slowly running drains. Also, listen for a distinct gurgling sound when sinks drain or when toilets flush. Both of these symptoms suggest a clogged drain vent. It is possible to clean and unclog a plumbing vent on your own, but amateurs should call in a plumber. Competent plumbers can also diagnose broken drain pipes even when located under the yard.
6. Actual Rotten Eggs
Sometimes if it looks like a rotten egg and smells like a rotten duck egg, it’s a rotten egg. Expired eggs and other spoiled food items create all manner of foul odors throughout your home. Though eggs last a while before spoiling, the same is not true of other ingredients like chicken, avocado, green beans, bananas, mushrooms, and others. Additionally, cooked ingredients can spoil and emit disgusting smells, so keep an eye on your cold-pressed juices and whatever leftovers lying in the refrigerator.
What to Do
Clear out the offending ingredients, throw them in the trash, and immediately throw out the trash. After that, clean the refrigerator with a multi-purpose cleaner and install a mild air freshener in your kitchen or in the fridge. Also, set your refrigerator’s thermostat to 40 degrees Fahrenheit or below to stave off early spoiling.
