A sudden rotten egg or sulphur-like odour inside your home should never be ignored. Natural gas is naturally odourless, so utilities add an odorant called mercaptan to make a possible leak easier to detect. If you smell natural gas in house areas such as the basement, kitchen, mechanical room, or near a gas appliance, the safest response is to treat the situation seriously. A natural gas leak can create a fire or explosion hazard, and trying to determine the source yourself can put you and others at unnecessary risk.
Comfort Living HVAC helps London-area homeowners understand gas appliance and Gas Pipeline safety, but an active suspected gas leak is an emergency first and an HVAC service issue second. If you smell natural gas in house, leave the area immediately, keep other occupants away, and call 911 and your gas utility from a safe location. Enbridge Gas advises Ontario customers who smell gas to leave immediately and call for help once they are safely away. Do not stay inside to troubleshoot the Furnace, Tankless Water Heater, Gas Pipeline, or other fuel-burning equipment.
Why Natural Gas Has A Rotten Egg Smell
Natural gas itself does not normally have a noticeable odour. Gas utilities add an odorant so people can recognize a potential leak before the gas reaches dangerous concentrations. The result is often described as a rotten egg or sulphur smell. If you suddenly smell natural gas in house areas where gas appliances or piping are located, you should assume that a leak may be present rather than trying to determine whether the smell is strong enough to be dangerous. Enbridge Gas identifies a rotten egg or sulphur smell as one of the main warning signs of escaping natural gas.
The smell may be noticed near a Furnace, fireplace, stove, water heater, Tankless Water Heater, Gas Pipeline connection, meter, or another gas appliance, but you should not remain inside searching for its exact source. Gas may move through indoor spaces, and the location where you first notice the odour may not identify where the leak actually began. If you smell natural gas in house, your priority should be evacuation and contacting emergency professionals, not inspecting appliances or pipe fittings.
Other Signs That May Accompany A Gas Leak
A rotten egg odour is the most recognizable warning sign, but Enbridge Gas also identifies hissing or whistling sounds, bubbling water, damaged connections, unexplained dying vegetation, and blowing dirt near gas lines as possible warning signs. You do not need to see several warning signs before acting. If you smell natural gas in house or strongly suspect gas is escaping, leave immediately and contact emergency services from a safe location.
Do Not Confuse Natural Gas With Carbon Monoxide
Natural gas and carbon monoxide are different hazards. The odorant in natural gas can make a leak smell like rotten eggs, while carbon monoxide has no smell, taste, or colour. Health Canada explains that carbon monoxide is produced when fuels such as natural gas burn and can accumulate when fuel-burning appliances malfunction, are poorly maintained, or are not properly vented. A natural gas smell requires immediate evacuation, while a sounding carbon monoxide alarm also requires leaving the home and calling 911.
What To Do Immediately If You Smell Natural Gas
If you smell natural gas in house, stop what you are doing and get everyone outside. Do not spend time collecting belongings or trying to confirm whether the odour is coming from a particular appliance. Enbridge Gas advises people who detect a gas leak to leave the premises immediately and call for help only after reaching a safe location. If children, visitors, or pets are inside, bring them with you if doing so does not delay evacuation or create additional danger.
Once safely outside and away from the suspected leak, call 911 and your gas utility. For Enbridge Gas customers in Ontario, the emergency line is 1-866-763-5427 and is available 24 hours a day, seven days a week. Follow the instructions provided by emergency responders or the utility. Do not return to the home simply because the smell appears to have disappeared.
Leave Before Making The Call
Do not use your phone while you are still inside the building or near the suspected leak. Enbridge Gas advises against using phones, switches, electronics, appliances, or anything that could create a spark in the affected area. If you smell natural gas in house, move to a safe distance first, then make the emergency calls.
Keep Everyone Away From The Property
Once outside, keep household members and visitors away from the building until emergency professionals determine it is safe. Do not allow someone to go back inside to retrieve belongings, check an appliance, open additional windows, or turn off equipment. The safest approach is to leave inspection and control of the suspected leak to trained professionals.
What You Should Never Do During A Suspected Gas Leak
When people smell natural gas in house, a common instinct is to find the source and stop it. That response can be dangerous. Do not inspect fittings with tools, attempt to tighten gas connections, move appliances, relight pilot lights, open equipment panels, or attempt Gas Pipeline repairs. Enbridge Gas specifically warns people not to search for or repair a gas leak themselves. Even if you have previously performed home repairs, an active gas leak is not an appropriate DIY project.
You should also avoid creating potential ignition sources. Do not switch lights on or off, operate appliances, use a garage door opener, smoke, light candles or matches, start a nearby vehicle, or operate electrical equipment in the affected area. Enbridge Gas lists these actions among things to avoid when a gas leak is suspected. If you smell natural gas in house, leaving immediately is safer than trying to make the building safer yourself.
Do Not Turn Electrical Equipment On Or Off
A switch can create a small electrical spark. In the presence of a flammable gas-air mixture, even a small ignition source may be dangerous. Leave lights, fans, HVAC equipment, and appliances as they are while you evacuate. Do not turn on an Air Condition system or ventilation fan in an attempt to remove the smell.
Do Not Attempt To Shut Off Gas Unless Directed
Homeowners sometimes assume they should immediately shut the main gas valve themselves. During a suspected active leak, the safer general instruction is to evacuate rather than remain in the area manipulating gas equipment. Follow the directions of your gas utility or emergency responders. Do not attempt Gas Pipeline work unless you are properly qualified and specifically authorized to do so.
When To Call 911 And Your Gas Utility
If you smell natural gas in house, calling 911 and the gas utility from a safe location is appropriate. Enbridge Gas tells Ontario customers to call 911 if they smell or hear gas escaping and then contact the company’s emergency line. You do not need to wait until the smell becomes overwhelming, and you should not dismiss the odour simply because it seems to come and go.
Emergency responders and the utility have procedures and detection equipment for evaluating suspected gas leaks. They can determine when an area is safe and whether gas service must be shut off. Comfort Living HVAC should become involved only after the immediate emergency has been controlled and the building is considered safe to enter. At that point, a qualified gas technician can inspect a Furnace, Tankless Water Heater, Gas Pipeline, or another gas-fired appliance that may require service.
If The Odour Seems Very Strong
A strong smell does not change the basic safety procedure. Leave immediately and keep moving to a safe distance. Do not stop to determine whether the odour is strongest near the basement, meter, kitchen, or mechanical room. Once safe, call 911 and the gas utility.
If The Smell Seems Weak Or Intermittent
A faint or occasional smell should not automatically be treated as harmless. Gas leaks can vary, and household airflow may affect where the odour is noticed. If you genuinely believe you smell natural gas in house, it is safer to leave and report the concern rather than waiting for the smell to become stronger.
A Quick Safety Checklist If You Smell Gas
A gas emergency can be stressful, which makes simple instructions useful. The priority is not to diagnose the Gas Pipeline or determine which appliance has failed. Your goal is to get people away from the suspected leak without creating an ignition source. If you smell natural gas in house, remember that professionals can investigate the equipment after everyone is safely outside.
Use this safety checklist:
- Leave the home immediately.
- Bring household members and pets with you when safe to do so.
- Do not use switches, phones, electronics, or appliances inside.
- Do not smoke or use matches, candles, or lighters.
- Do not start a vehicle near the suspected leak.
- Do not search for the source.
- Do not attempt a Gas Pipeline or appliance repair.
- Call 911 from a safe location.
- Call your gas utility’s emergency number from a safe location.
- Stay away until authorities say it is safe to return.
These steps follow the same overall approach recommended by Enbridge Gas for suspected natural gas leaks.
What Happens After You Report A Gas Smell?
After you report that you smell natural gas in house, the gas utility or emergency responders may investigate the property and surrounding gas infrastructure to determine whether gas is escaping. Depending on what they find, they may isolate the area, shut off gas service, identify unsafe equipment, or provide instructions about what needs to happen before service can be restored. Do not assume that because the odour disappears while you are outside, the property is safe to re-enter.
If an appliance or private gas piping issue is identified, you may need a qualified contractor to make repairs before the appliance or gas service can safely return to normal operation. This is where Comfort Living HVAC can assist with relevant Gas Pipeline, Furnace, or Tankless Water Heater concerns after the emergency authority or utility has made the area safe. Comfort Living HVAC should not be your first call while an active leak is suspected. Emergency responders and the gas utility come first.
Do Not Re-Enter Until You Are Told It Is Safe
Enbridge Gas advises people not to re-enter a building after a gas emergency until it has been inspected. Wait for explicit instructions rather than assuming that enough time has passed or that opening a door has made the property safe.
Appliance Repairs Come After Emergency Control
If the investigation points to a Furnace, Tankless Water Heater, fireplace, stove, or another gas appliance, qualified service may be needed. Any affected gas appliance should remain off until it has been properly inspected and determined to be safe for operation.
Natural Gas Leaks And Carbon Monoxide Are Not The Same Problem
Many homeowners associate gas appliances with carbon monoxide, but the hazards are different. When you smell natural gas in house, you may be detecting the odorant intentionally added to the gas supply. Carbon monoxide cannot be detected by smell. Health Canada explains that CO is colourless, tasteless, and odourless and can be produced by furnaces, gas water heaters, fireplaces, and other fuel-burning equipment.
This distinction is important because not smelling natural gas does not prove that a fuel-burning appliance is operating safely. Health Canada recommends having fuel-burning appliances inspected by a qualified professional at least annually or according to manufacturer instructions and maintaining certified carbon monoxide alarms near sleeping areas. Comfort Living HVAC can help maintain relevant Furnace and Tankless Water Heater equipment after any immediate safety concern has been resolved.
What To Do If A CO Alarm Sounds
Health Canada advises occupants to leave the home immediately, move to fresh air, and call 911, the fire department, or emergency services after getting outside. Do not search for the source yourself and do not return until professionals say it is safe.
Annual Gas Appliance Maintenance Matters
Regular professional maintenance can identify problems involving appliance operation, venting, connections, and combustion before they become more serious. Health Canada recommends regular inspection of fuel-burning appliances and checking natural gas equipment for leaks, poor connections, blocked vents, and other defects.
Common Sources Professionals May Investigate
Once the emergency has been controlled, trained professionals may investigate several possible sources if you reported that you smell natural gas in house. These can include gas piping and connections, a Furnace, a Tankless Water Heater, fireplaces, ranges, dryers, or other gas appliances. The exact diagnostic process depends on the property and what emergency responders or the utility found. Homeowners should not attempt to reproduce these tests themselves.
A professional assessment may also reveal that the original smell was not caused by a leak from an appliance. Even so, reporting a genuine natural gas concern is the safer choice. Comfort Living HVAC can inspect relevant Gas Pipeline and heating equipment once the property is cleared for service. The important distinction is that diagnosis and repair occur after immediate safety measures, not while people remain inside a building where gas may be escaping.
Furnace And Heating Equipment
Gas furnaces contain fuel connections, controls, burners, and venting systems that require qualified inspection. If a Furnace is identified as a possible source after the emergency is controlled, keep it off until a qualified technician has inspected it.
Tankless Water Heaters And Other Gas Appliances
A gas-fired Tankless Water Heater also relies on proper fuel connections and venting. Gas stoves, fireplaces, boilers, dryers, and other appliances may be part of an investigation as well. If you smell natural gas in house, do not move or test these appliances yourself.
How To Reduce Future Gas Safety Risks
No maintenance program can guarantee that a leak will never occur, but responsible gas appliance care can reduce avoidable risks. Have fuel-burning appliances serviced according to manufacturer requirements and applicable professional recommendations. Pay attention to physical damage, unusual appliance operation, corrosion, blocked exterior vents, and changes around mechanical equipment. Health Canada advises homeowners to regularly examine natural gas-powered appliances for leaks, cracks, blocked vents, improper installations, poor gas-line connections, and damaged venting.
Professional care is particularly important because gas equipment interacts with several home systems. A Gas Pipeline must safely deliver fuel, a Furnace must burn and vent it correctly, and a Tankless Water Heater requires proper gas supply and exhaust arrangements. Comfort Living HVAC can help London homeowners maintain relevant equipment and identify service concerns. Still, if you ever smell natural gas in house again, maintenance history does not change the emergency response. Leave first and report the suspected leak.
Keep Exterior Vents Clear
Health Canada recommends checking exhaust vents during and after snowstorms to make sure they are not blocked by snow, ice, or debris. This applies to vents serving furnaces, fireplaces, dryers, and other fuel-burning appliances.
Schedule Professional Gas Appliance Inspection
Gas-fired equipment should be maintained according to manufacturer instructions and inspected by qualified professionals. Professional inspection can help identify deterioration or operating conditions that homeowners cannot safely evaluate themselves.
Why Choose Comfort Living HVAC
Comfort Living HVAC understands that gas safety must come before equipment repair. If you smell natural gas in house, our first recommendation is not to troubleshoot the HVAC system. Leave immediately and contact 911 and the gas utility from a safe location. Once emergency professionals confirm that the property is safe and identify a repair need involving privately owned equipment, Comfort Living HVAC can assist with appropriate Gas Pipeline, Furnace, or Tankless Water Heater service.
Our team serves London-area homeowners who need clear recommendations after a gas-related concern has been brought under control. We can evaluate relevant gas-fired equipment, explain identified faults, and discuss repairs or maintenance required before normal operation resumes. Comfort Living HVAC does not encourage homeowners to perform DIY gas repairs. Gas connections and fuel-burning equipment should be handled by qualified professionals using appropriate safety procedures.
Take A Natural Gas Smell Seriously Every Time
If you smell natural gas in house, do not wait to see whether the odour disappears and do not remain inside searching for its source. Leave the property, keep others away, and call 911 and your gas utility from a safe location. Avoid switches, electronics, open flames, smoking, vehicles near the suspected leak, and DIY repairs. These precautions are simple because the safest response is evacuation rather than investigation.
After emergency professionals confirm that it is safe to return, Comfort Living HVAC can assist if the issue involves your Gas Pipeline, Furnace, Tankless Water Heater, or related gas-fired equipment. If an inspection or repair is needed after the emergency has been controlled, contact Comfort Living HVAC for professional gas line and appliance support. Safety comes first, and any repair work should begin only after the immediate gas leak concern has been properly addressed.
Frequently Asked Questions
Knowing what to do before an emergency happens can make your response faster and safer. The most important rule is that a suspected natural gas leak is not a DIY troubleshooting situation. If you smell natural gas in house, leave immediately and contact emergency professionals from a safe location.
The following questions address common concerns London-area homeowners may have about gas smells and gas appliance safety. They are intended to reinforce emergency actions, not provide instructions for locating or repairing a leak.
1. What Should I Do First If I Smell Natural Gas In House?
Leave the property immediately and take other occupants with you if it is safe to do so. From a safe location, call 911 and your gas utility. Do not remain inside looking for the leak.
2. Why Does A Gas Leak Smell Like Rotten Eggs?
Natural gas is normally odourless. An odorant is added so leaks can be detected more easily. Enbridge Gas describes the warning odour as similar to rotten eggs or sulphur.
3. Should I Turn Off The Lights If I Smell Natural Gas In House?
No. Do not turn electrical switches or appliances on or off. Enbridge Gas advises avoiding switches, phones, electronics, appliances, and other possible ignition sources while leaving the affected area.
4. Should I Open Windows If I Smell Gas?
Do not delay evacuation to ventilate the house. Your priority is to leave immediately. Follow the instructions given by emergency responders or your gas utility once you are safely outside.
5. Can I Look For The Gas Leak Myself?
No. Enbridge Gas advises people not to search for or repair suspected gas leaks themselves. Gas Pipeline and gas appliance diagnosis should be performed by qualified professionals after the area is safe.
6. Is A Rotten Egg Gas Smell The Same As Carbon Monoxide?
No. Natural gas odorant can smell like rotten eggs, while carbon monoxide has no smell, colour, or taste. Health Canada says a CO alarm is required to detect carbon monoxide.
7. When Should I Call Comfort Living HVAC After I Smell Natural Gas In House?
Call Comfort Living HVAC after emergency responders or your gas utility have determined that the property is safe and a repair or inspection is needed for your Gas Pipeline, Furnace, Tankless Water Heater, or other relevant gas-fired equipment.
