How to Tell if You Have a Gas Leak in Your Home
- To The T Plumbing and Heating
- Mar 25, 2021
- 4 min read
Updated: 3 days ago

Natural gas and propane can provide an efficient way to power your home’s hot water, heat, and appliances. But if a gas line has a problem, you can end up with a household gas leak on your hand. Unfortunately, natural gas won’t always emit a smell when it escapes. That means you can have a home gas leak and not even know it!
Gas leaks can cause many health problems and can even be deadly in some cases. With so much at risk, the last thing you want to do is let a gas leak continue for too long. Gas leaks aren’t always easy to spot. But there are a few ways you can tell if gas might be escaping in your home.
Health Symptoms Associated With a Gas Leak
It’s not ideal, but sometimes the first sign of a gas leak is how you feel. If you or your family suddenly start feeling unwell, it could be a warning that gas is leaking into your home.
Gas leaks will change the oxygen levels in your home. This will vary in severity based on what kind of leak you’re dealing with. But these are the general symptoms you might experience:
Dizziness
Nausea
Headaches
Eye or throat irritation
Issues breathing (respiratory problems)
Chest pain
Can You Smell A Gas Leak
Sometimes, yes, but not always. Natural gas doesn’t have a smell.
That’s why utility companies add a chemical called mercaptan. It gives off a strong odor, like rotten eggs or sulfur. That smell is your warning sign.
But here’s the catch: some leaks don’t smell strong enough to catch your attention. In other cases, other household smells can cover it up, or the scent can fade over time. So while your nose can help, it’s not something you should rely on completely.
What does a gas leak in a house smell like?
If you do catch a whiff, you’ll know something’s off. Most people describe it as a rotten egg smell. Others say it’s like a skunky odor or even a bit metallic.
If you notice a weird smell that just won’t go away (especially near your stove, heater, or gas lines) it’s better to play it safe. Step outside, call your gas company, and let the pros (hey, that’s us!) check things out.

Symptoms of a Gas Leak in the House
Hissing Sound
Sometimes a natural gas leak in the house will emit a low hissing sound. This usually means gas is escaping at a fairly fast rate. Any noise coming from your HVAC system usually isn’t a good sign. A leaking valve, loose refrigerant line, or faulty compressor might be causing the hissing sound.
Dying House Plants
A gas leak can be unhealthy for all living things. Your plants might produce oxygen but they also need a supply of it to survive. If they don’t have enough of it, they will slowly start to die.
House plants could end up being your canary in a coal mine if you have a gas leak. If several of your plants start withering, even though you’re watering them, it could be a sign of a gas leak.
Mist or Fog
Sometimes a gas leak will create a fine mist or odorless haze in the house. In most cases, gas leaking from an underground supply line causes this. Condensation collects and forms a low-hanging, unnatural haze around your home.
Your Gas Bill is Higher
Gas leaks are subtle in smell but very obvious in bills. They can even go on for months undetected. But if there’s a significant amount of gas escaping from your system, it can cause a spike in your gas bill.
Pay attention to any sudden changes in your monthly invoice. If you notice a huge, unexplainable increase in your charges, you should have your system inspected for leaks.
Rotten Egg Smell
Natural gas has no smell. However, utility companies add a substance to the gas in your home. This helps you detect leaks more easily.
People often describe this chemical as smelling like rotten eggs or sulfur. Leaks won’t always have this smell. If you smell this odor, leave your house right away. Then, call an emergency HVAC professional.
How to Check for a Gas Leak in the House
Bubble Test
If you notice other signs of a gas leak but still aren’t sure, you can use the bubble test. What you’ll want to do is:
Fill a container with water and dish soap.
Bring it to the source of the suspected leak.
Now wipe the soapy water onto the area in an even coat.
Wait and watch to see if any bubbles start to form. If the solution starts to bubble, you likely have a leak.
What Do I Do When I Discover a Gas Leak
If you notice any sign that you have a gas leak, exit your home and call a professional to inspect your system ASAP. If you have a carbon monoxide leak, you could lose consciousness in just 3 hours so it’s important to act fast. You might call your utility company first, but they’ll only shut off your gas. Instead, call a plumbing or HVAC expert for more help.