10 Things That Could Be Causing That Funky Smell in Your House

Lawrence Bonk
Written by Lawrence Bonk
Updated March 22, 2022
An open-plan sitting and dining area in a cottage house
Photo: Andreas von Einsiedel / Corbis Documentary / Getty Images


  • Many underlying issues contribute to foul smells in the home. 

  • Mold smells musty and contributes to respiratory issues. 

  • Gas leaks often reek of rotten eggs. 

  • Certain electrical problems create an unpleasant fish smell. 

  • Plumbing issues, volatile organic compounds (VOCs), and low-quality drywall can cause foul odors.

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Your home is your sanctuary, and sudden unpleasant smells can burst that relaxing bubble quicker than you can say, “ew, sulfur.” Before performing steps to keep your home smelling fresh and clean, you need to understand what causes these funky odors. Here are 10 things that could be causing some unexplained smells in your house, from the expected to the absolutely surprising—and what you can do about them.

1. Mold, Mildew, and Dust

Ah, yes, the infamous trinity of mold, mildew, and dust. Each contributes to household odors in its own way, though mold presents some legitimate health risks. This foul fungus thrives in moisture, so take care of leaks ASAP, as mold can aggravate respiratory and allergy problems. 

You can keep dust and mildew at bay by performing regular cleaning tasks like sweeping and dusting and laying down an air purifier or two. For mold, keep a constant eye on your basement and bathrooms and consider installing a dehumidifier (mold hates dry air). If you spy a large outbreak of mold, contact a local mold remediation service to nip it in the bud before it spreads its loathsome spores throughout the home.

2. A Gas Leak

If you smell rotten eggs and are fairly certain your carton is in the refrigerator where it belongs, a gas leak is a likely culprit. Natural gas is actually completely odorless, but gas companies add an odorant that creates that tell-tale sulfur smell. This smell helps homeowners suss out gas leaks as soon as possible, allowing them to flee the home and contact authorities. 

Gas leaks are extremely dangerous, causing fires, explosions, and even respiratory failure. If you suspect a gas leak, do not turn on any appliances or use your landline. Instead, vacate the premises immediately and call your gas company’s emergency line for more instructions. 

3. Electrical Problems

Believe it or not, overheating or burning electrical components creates a fishy smell throughout the home. So if you smell fish somewhere, it’s more likely frayed wires than an errant salmon. All manner of electrical problems contribute to these odors, including loose cords, overloaded circuits, faulty outlets, incorrectly sized breakers, overheated electrical shielding, and more. 

Beyond fish, many electrical issues lead to funky smells, which you can get rid of burning or smoky smells using these tips. Be sure to contact a local electrician right away if you encounter these odors.

4. Problematic Drywall

If someone cuts corners during the home building process, you may later be dealing with problem drywall. Like gas leaks, this type of low-quality drywall emits a sulfur smell (rotten eggs.) Other tell-tale signs of this low-grade drywall include the early failure of HVAC systems, tarnished silver jewelry, and copper wires coated in a black residue. The US Consumer Product Safety Commission lists other identifying signs here to help you narrow down this problem. 

If you suspect the presence of this problem drywall, call in a local drywall repair pro to assess it, and possibly have them replace it.

5. Plumbing Issues

A white bathroom with a bathtub and two sinks
Photo: michaelmjc / iStock / Getty Images Plus / Getty Images

A whole spate of plumbing issues causes foul odors throughout the home, particularly in and around bathrooms and the basement. Noticing an icky sewage smell wafting around your home? It’s likely related to a plumbing issue. 

The cause of this “bathroom smell” varies, from dried-up P-traps to clogged pipes, damaged anode rods, or a backed-up sewage drain. Run water through all drains at least once a month to minimize these issues and contact a local plumber for help identifying and fixing the source of the problem.

6. VOCs

Volatile organic compounds (VOCs) can be present in multiple locations throughout the home, from hairspray to plywood, and each creates its unique odor. Common VOCs include formaldehyde, butane, ethylene glycol, acetone, and methylene chloride. 

The smell goes away when you eliminate the source, so toss old cleaning agents, paint cans, and hairspray, among other items. For particleboard and certain types of plywood, act with caution when purchasing such items, searching for brands advertising little to no additional VOCs. It is virtually impossible to avoid all VOCs in daily life, but a little diligence goes a long way.

7. Pest Problems

Homes feature plenty of nooks and crannies for rodents and other pests to create secret hideaways. Pests are never going to make your home smell good, and unfortunately, the circle of life means that these co-habitants may perish in your walls. If multiple rodents or even one large mammal dies and rots behind a wall, your nose will let you know. 

Contact a local animal removal company and move that smell of decay away from your home. Many of these companies also disinfect the impacted areas upon removal. 

8. Pet Messes

We love our furry feline friends, but if they have an accident in the home, the smell can linger. If you have an alpha cat trying to mark its territory in your home, you’ll also likely encounter the oh-so-nasty smell of cat spray. 

However, pet owners know what to do here: Keep an eye on their cats and clean as necessary. In some cases, though, you may not catch every incident, or the smell could be coming from the missteps of the home’s previous owner. Luckily, a local floor-cleaning service specializing in animal waste can help you here. 

It’s also important to note here that some issues in the home mimic the smell of cat urine, including certain types of mold and landscaping shrubs like ornamental boxwood. If you don’t have a cat, these are also worth keeping in mind.

9. Old Food

Food may smell delicious at first, but give it a few days on the counter, and it won’t smell the same. If someone accidentally dropped a bit of their sandwich or left lunch in your home office, you’ll know by the rotting stench before too long. 

The fix here is simple. Maintain regular cleaning tasks, checking behind furniture and in various nooks and crannies every once in a while. Your garbage disposal is also a haven for rotting food debris. Clean and disinfect the appliance regularly.

10. Outside Odors

Sometimes, a funky smell seems to emanate from the home but actually comes from outside. Intense smells often travel long distances before reaching your door, so take a step outside and smell the funky roses before searching indoors for the source of any smell. 

Once confirmed, tighten up your home’s insulation to minimize unwanted odor-causing particles. Take on the cost to apply weatherstripping on windows and doors and, in severe cases, run air purifiers throughout your home. Also, stay current on your HVAC system’s air filters, cleaning or replacing as necessary.

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