Suspect a Furnace Gas Leak? Here’s What To Do!

furnace gas leak

Did you know that the natural gas furnace is the most common heating system found in homes in North America?

Did you also know that more than 80 million Americans use natural gas for heating, cooking, hot water, and other activities?

That’s a lot of people using natural gas!

So it’s not uncommon for any one of these loving homeowners or renters to occasionally smell gas from a furnace gas leak.

If your home has an older heating system or perhaps one that hasn’t been maintained very often, you would be more susceptible to smelling a small amount of gas.

But is it normal to smell gas in my home while I’m operating my furnace?

The short answer is yes!

But there are only certain times you should smell gas, and any more than that is a problem and health hazard.

So keep reading to learn more about if you suspect a gas leak and what you should do about it.

⭐ More About Natural Gas

gas burner

Natural gas is an odorless and flammable gas that’s formed deep beneath the earth from decaying dinosaurs.

Since it’s odorless and has the propensity to blow up your home, gas manufacturers add a chemical called mercaptan.

Mercaptan, also known as methanethiol, is a horrible-smelling gaseous chemical that’s made up of carbon, hydrogen, and sulfur.

It’s the sulfur you smell when natural gas is present.

Sulfur has a rotten egg smell, and it acts as an odorant to warn you of a leak.

Mercaptan is harmless to humans and animals in small quantities.

📗 Related Reading: What Does Sulfur Smell Like? A Homeowners Plumbing Guide

⭐ Is My Furnace Leaking Gas?

furnace leak detection
Phyxter Technician conducting furnace gas leak test

All natural gas-powered furnaces leak a little bit of gas. But how much is too much?

So it’s normal to smell gas near a furnace at the beginning of the heating cycle.

It becomes a problem when the smell is strong and doesn’t subside.

It’s even worse if you still smell it further away from your furnace.

⭐ What To Do If You Suspect a Major Gas Leak

If the smell of natural gas is strong throughout your home and doesn’t subside quickly, you must take immediate action.

A major gas leak is dangerous and can affect the health of your family and pets and also put your property at risk.

You don’t want to blow up your house and end up as the main headline on the local news.

This family died after a faulty gas water heater DIY installation.

🛑 Evacuate Your House Immediately

Warn everyone in your home to leave immediately. Don’t forget to grab your pets. If you have the chance, open all doors and windows on the way out.

Also, if the opportunity exists, without risking yourself, turn off your furnace at the thermostat and turn off the gas valve.

Also, avoid lighting matches if possible!

🛑 Call 911!

Once you and your family are a safe distance from your home and have safely evacuated, you don’t think you will die in a gas explosion, call 911 and your local gas company.

The local fire department will investigate the problem and inform your utility company of its findings.

🛑 Arrange an Inspection

Call your local professional HVAC contractor to inspect and assess the gas leak. If it’s minor, you will be back in your home in no time.

If it is a major problem, they will inform you of your options.

⭐ What Are The Health Risks Associated with a Gas Leak?

Gas leaks in your home can release harmful substances into the air.

If your gas leak is due to a cracked heat exchanger, you could inadvertently pump carbon monoxide (CO) into your home.

CO is an odorless and tasteless gas that is highly toxic.

It is essential that all of your home’s carbon monoxide detectors are in good working condition.

The most common symptoms of carbon monoxide exposure include flu-like symptoms, dizziness, chest pain, headaches, nausea, sinus irritation, and problems with breathing.

If anyone in your family group shows physical symptoms of carbon monoxide poisoning, contact 911 immediately or if you have already called, ensure you inform a first responder on the scene.

symptoms of carbon monoxide poisoning

⭐ Other Signs You Have a Gas Leak

There are a few other telltale signs you have a gas leak in your home.

Smelling rotten eggs and maybe showing carbon monoxide poisoning symptoms are the most dangerous that needs to be taken seriously when dealing with furnace gas leaks.

These are less common these days with modern gas furnaces, but there is still a chance for you to be affected by natural gas exposure.

Other signs can include:

🔊 Hissing Sound

hissing cat

If you can actually hear hissing sounds in or around your furnace and it’s not coming from the pet cat, and you can smell it, you definitely have a leak.

Leaking gas will make a sound as its leaking from the gas lines.

Try to pinpoint the location of the leaky gas line, this will help with the speed with which an HVAC technician can solve the problem and stop the leak.

🔥 Check Your Furnaces Pilot Flame

furnace ignitor

Pilot flames should always burn blue. This means the gas is burning completely. A yellow flame means incomplete combustion.

If your flame is anything but electric blue, you probably have a leak, and your furnace is producing carbon monoxide.

🌿 Dead Houseplants or Garden

dead houseplants

Plant life doesn’t like natural gas. The gas displaces oxygen in the soil and boosts the formation of hydrogen sulfide gas.

This gas inhibits nutrient absorption in plant roots leading to the death of the plant or grass.

Indoor house plants may start to die if you have an indoor gas leak.

If you have an outdoor leak from an underground pipe, the grass in the area will start turning brown as it slowly dies.

⭐ Finally!

Phyxter HVAC tech conducting furnace repair

Furnace gas leaks are not something you want to mess around with as the average homeowner.

Unless you’re experienced with gas furnaces and gas water heaters, then go ahead.

In our professional opinion, these issues are best left to a qualified technician.

If you suspect a leak from the warning signs listed above, call your local HVAC company and get a professional HVAC contractor to check it out.

Recognizing the signs of a gas leak and responding appropriately is essential to maintain the safety of everyone in your home, including those beloved animals.

If you live in the North or Central Okanagan region, call Phyxter Home Services.

We have friendly furnace repair experts ready to help with any of your heating, HVAC system or air conditioning needs.

Related Reading: How to Diagnose and Repair a Bad Furnace Ignitor

Russell Jones

Russell, a native Australian and VP of Operations at Phyxter Home Services, is also part-owner of Vernon Air Conditioning, Plumbing, and Electrical Services. When he's not busy with work projects and renovations, Russell enjoys putting his vast knowledge of home improvement to good use by sharing his tips and tricks.

About our blog

Phyxter (pronounced Fix-ter) is a national home services brand specializing in Residential HVAC, Electrical and Plumbing solutions.

Phyxter is laser-focused on writing the best articles and guides to empower homeowners to get the best out of their homes.

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