Lifestyle

7 Signs of a Gas Leak at Home That Are Easy to Miss, Especially as You Get Older

By Curtis Jones · November 3, 2026

With the heating season here, it helps to know what a gas leak looks, sounds and smells like. Natural gas and propane are flammable, and the National Fire Protection Association says leaks inside homes continue to cause fires and explosions every year.

Natural gas has no smell of its own. According to the American Public Gas Association, utilities add an odorant called mercaptan so people can tell when gas is in the air. Smell is only one clue, though.

These are the warning signs listed by the APGA, the Indiana Utility Regulatory Commission, the Propane Education & Research Council and the NFPA.

A rotten egg or sulfur smell. The APGA describes mercaptan’s odor as similar to sulfur or rotten eggs.

A hissing, roaring or whistling sound. The Indiana Utility Regulatory Commission says a leak can sometimes be heard as an unusual roar, hiss or whistle. The propane council says a hissing sound may mean gas is escaping from part of a propane system or an appliance.

Dead or dying plants or grass. Both the APGA and the commission list an area of dead or dying plants or grass as a possible sign of a leak outdoors.

Bubbling water or blowing dirt. The APGA lists bubbling water and blowing dirt. The commission adds that soapy water applied to gas connection points may show bubbles forming.

A white cloud or frozen ground. The commission also lists a white cloud or vapor, and frozen ground when it is warm outside.

A headache or light-headed feeling. You may feel light-headed or have a headache if gas begins to displace oxygen in a room, the commission says.

Using more gas than expected. The propane council says that if you are using more gas than you expect, there may be a leak.

Why the nose can fail. The propane council lists several reasons people may not notice the odor, including a cold, allergies or sinus congestion, being asleep, and being older. It also describes “odor fatigue,” when steady exposure makes the nose less sensitive, and says other strong smells such as cooking can mask it. The NFPA says studies show the sense of smell can stop registering the same odor after a minute or two, and that people who are asleep or away will not notice a leak at all.

That is why these groups recommend a fuel gas detector. The APGA says one can help if you have a weak sense of smell. The NFPA notes that its standard, NFPA 715, covers where such alarms go when required, including near fuel-burning appliances and outside sleeping rooms. The propane council says to treat an alarm as an emergency even if you smell nothing. A gas alarm is not the same as a carbon monoxide alarm, the NFPA says, and homes with fuel-burning appliances need both.

If you suspect a leak, the APGA’s advice is to stop, leave and call. Don’t light a match, smoke, start a car, flip a light switch, or touch appliances or electronics, including your phone. Leave right away and take others with you. Once you are a safe distance away, call 911 and your gas utility or propane supplier. The commission advises against opening windows to air out the house and says not to try to find or fix the leak yourself. Don’t go back until the utility or emergency responders say it is safe, the NFPA says.

Outdoors, the commission says the leading cause of leaks is damage to pipelines from digging, so call 811 before any digging project.

This article is for general information. If you smell gas or a gas alarm sounds, leave right away and call 911 or your gas provider from a safe distance. This article was produced with the assistance of AI and fact-checked against the sources cited by LightWave Reports.