House Smells Like Skunk? Gas, Sewer and Other Odor Causes

A skunk-like smell does not tell you what caused it. The source could be skunk spray or odorized natural gas; sewer gas and dead animals can produce a similar odor. Rule out a gas leak first. Once the utility or fire department clears the building, pay attention to where the odor appears and what was running when it started.

First: rule out a gas emergency

Natural gas has no smell on its own, so utilities add an odorant to make a leak easier to notice. PHMSA says that warning odor may smell skunk-like. Your nose can get used to the smell, so do not judge the risk by its strength. Leave if it starts suddenly or spreads through the house. The same rule applies when the odor is near a gas appliance or meter. Hissing is another reason to get out. For suspected utility gas, call 911 and the gas utility before calling an emergency plumber.

Do not walk from room to room comparing the smell. Do not check burners or search for a leak. Leave the windows alone and get outside.

What can smell like skunk indoors?

Wait until the utility or emergency responders rule out natural gas before using this matrix. The clues can point you in a direction without proving the cause. Move to fresh air if anyone has trouble breathing or feels dizzy. Call 911 for a collapse or severe eye pain, and get medical help for symptoms that do not improve.

If the smell points to a drain or fixture after gas has been ruled out, compare the other common plumbing odors that can help narrow the source.

Why plumbing can create a skunk-like or sewer odor

Your drains carry wastewater away while each P-trap holds enough water to block sewer gas from coming back into the room. The plumbing vents keep pressure from pulling that water out of the trap, so the two parts work together.

A dry P-trap

A P-trap needs water to keep sewer gas out, and that water can evaporate in a seldom-used bathroom or laundry area. Floor drains are easy to forget; the U.S. EPA identifies them as a common trouble spot. Once gas has been ruled out, pour water into the unused drain. Call a plumber if the smell comes back soon because the trap may be leaking or losing its seal.

A loose cleanout plug or failed toilet seal

A missing cleanout plug gives drain-system air a way into the room, and a failed seal under a toilet can do the same. A toilet that rocks when you sit on it is one clue; dampness around the base is another. Leave the toilet and plug in place so a plumber can inspect the connection. See our toilet repair service page for more about that work.

A blocked or damaged plumbing vent

A restricted vent changes the pressure in the drain system as wastewater moves. Listen for gurgling and watch the water in a toilet while another fixture drains; tell the plumber if either one changes. A cracked vent inside a wall can also release odor. Roof access and vent clearing belong to a qualified professional.

A main-line or septic problem

When several fixtures smell, the problem is likely beyond one sink or toilet. Slow or gurgling drains may mean there is a main-line blockage, while backed-up sewage needs prompt attention. If no blockage is found, the plumber may look for a cracked pipe or damaged vent. Wet or spongy soil near a septic tank is another warning sign. What the plumber finds will determine the next step. A blockage may call for drain cleaning, while a confirmed damaged pipe may require sewer repair. Elite Rooter also provides broader sewer-line service.

Safe checks you can make after gas is ruled out

Once the building has been cleared, write down the room and the time you noticed the odor. Add which fixture had just been used. You do not need to open any equipment.

An unused drain offers one simple test: pour water into it once, but stop if the drain backs up.

Stay at floor level while you look for a rocking toilet or damp floor. Listen for gurgling as another fixture drains. Leave the toilet and cleanout plugs in place, and do not enter a crawlspace or climb onto the roof.

If sewage starts backing up, stop using water and keep everyone away from it. A note such as "the odor appears when the upstairs shower drains" will help the plumber more than a guess about which part failed.

If one trap refill does not stop the odor, arrange an inspection. Our guide to how to get rid of sewer smell in a bathroom covers problems around a single fixture. An odor that keeps coming back or reaches several rooms needs an on-site diagnosis.

How Elite Rooter traces an unexplained plumbing odor

Not every office has the same inspection equipment, and the access or condition of a pipe may rule out a test. Ask the local team what it can provide before scheduling. The Elite Rooter location directory will point you to the office that serves your address.

Watch how symptoms guide a drain diagnosis

The homeowner in the video noticed that the odor appeared only when an upstairs fixture was in use. Downstairs, the water in a toilet moved at the same time. That clue led the plumber to check the drain and vent pressure. A camera showed standing water in a horizontal pipe. He then ran another test to tell a sagging line from an ordinary clog.

For your own call, write down which fixture was running when the odor appeared. Tell the plumber if another toilet bubbles or a drain gurgles at the same time. That detail can change which test comes next.

This Old House filmed the job without Elite Rooter’s involvement. Our summary paraphrases the video transcript, and the diagnosis shown there may not apply to another home.

Clean up the odor only after the source is controlled

Deodorizer will not make a gas leak safe or fix the source of sewer odor. If the problem is confirmed skunk spray, set affected fabrics aside and follow their care labels. Use a product labeled for skunk odor or follow current Poison Control guidance. Never mix cleaning chemicals.

Skunk spray usually causes short-term irritation, though the National Capital Poison Center says it can sting the eyes and irritate the lungs. The odor can also worsen asthma symptoms for some people. If spray gets in the eyes, rinse them gently with room-temperature water for 15 minutes. Seek medical care for serious symptoms or irritation that does not improve, and never put a household deodorizing mixture in the eyes or mouth.

For sewer odor, repair the opening that let it into the room. Once a plumber confirms the problem is fixed, ordinary cleaning and fresh air can handle what remains. If the HVAC system carried a confirmed non-gas odor through the house, check the equipment instructions before replacing an accessible filter and call an HVAC professional for anything beyond that.

Once the underlying problem has been corrected, use our guide to clean a smelly drain without masking a recurring plumbing issue.

Prevent the smell from returning

Run water from time to time in drains that rarely get used, including those in a guest bathroom or basement. Remember a garage or laundry drain that may sit dry for weeks.

Have a plumber look at any odor that returns after a trap refill. More water will not repair a leaking trap or vent problem; a rocking toilet and recurring gurgling also deserve attention.

Keep outdoor trash and pet food secured, and call a wildlife professional if an animal moves under a deck or into a crawlspace. On a septic property, a backup or wet soil near the tank calls for a licensed septic provider.

When to call a plumber

Call the gas utility or 911 first if natural gas is possible. Once gas is ruled out, call a plumber when the odor is strongest at a drain or toilet or when it returns after one trap refill. If the smell returns alongside slow or gurgling drains, professional drain cleaning may be appropriate after a plumber confirms a blockage. Moving toilet water also points to a plumbing inspection. Stop using water and call promptly if sewage backs up.

The location directory will show which office serves your address and what inspection services it provides. It lists Phoenix and Denver along with San Diego and Tampa.