Smell Gas Near Your Furnace in Calgary? Get Out, Then Call ATCO Gas
Get everyone out of the house now — do not switch anything on or off, do not use a phone indoors, do not start a car in an attached garage. From outside, call ATCO Gas at 1-800-511-3447; if the smell is strong or you can hear gas, call 911 as well. Only after the utility has made the property safe do you call HVAC Lines for the repair.
Natural gas has no smell of its own; the rotten-egg odour is an additive put there so you notice a leak at a tiny concentration. A Calgary house in winter is sealed tight against the cold, with the windows shut and the furnace, water heater and often a fireplace all burning gas in the basement, so a small leak has nowhere to go. That is why the instructions on this page are blunt: the risk is not the smell, it is the spark — a light switch, a doorbell, a garage-door opener, a phone — meeting gas that has pooled in a closed room.
This page is for the moments after you are safely outside and have made the call. It covers what ATCO Gas does when they arrive and what they do not, who is legally allowed to repair the appliance afterwards in Alberta, how a carbon monoxide problem differs from a gas leak, and the handful of smells that are not gas at all.
What to do, in order
Leave, all of you, right away
Take people and pets out of the house. Leave the door open behind you if you can do it on the way out; do not go back in for anything. If the smell is in the garage, do not start or unplug a car.
Touch nothing electrical on the way
No light switches on or off, no thermostat, no garage-door button, no doorbell, no appliance. A switch makes a spark. If the lights are on, leave them on.
Call ATCO Gas from outside: 1-800-511-3447
Make the call from the sidewalk or a neighbour's, not from inside. Tell them where the smell is and how strong. ATCO Gas attends suspected leaks around the clock.
Call 911 if it is strong or hissing
A faint whiff is a utility call. A smell that hits you at the door, a hiss at the meter or a line, or anyone feeling dizzy or sick is a 911 call as well — the fire department will ventilate and check the house.
Wait outside until you are told it is safe
The utility technician finds the leak, shuts the gas at the meter or the appliance, checks the house with a detector, and tells you when you may go back in. Do not re-enter to open windows or check the furnace yourself.
Then call us for the repair
The utility makes the property safe; it does not fix your furnace. Once you are cleared, call (825) 395-7447 and our assistant connects you live to a technician from our network holding an Alberta gasfitter certificate, Class B or Class A to repair whatever leaked and relight the appliances.
Call a professional immediately if…
- You smell gas at all, anywhere in the house. There is no “mild enough to wait”.
- You hear a hiss near the meter, the furnace, the water heater or a fireplace.
- Anyone in the house has a headache, is dizzy or nauseous, or is unusually drowsy — that may be carbon monoxide rather than gas, and the response is the same: out, then 911.
- A gas appliance has a yellow, lazy flame instead of a crisp blue one, or there is soot around it.
- The gas meter outside has been struck by a vehicle, buried by a snowplough, or damaged by ice falling from the roof.
What happens once you call
ATCO Gas will have shut off and red-tagged whatever leaked: a fitting on the furnace, a flexible connector, a valve, a section of line. Their job ends at safe. The repair — replacing the part, pressure-testing the line, relighting the water heater and furnace — is done by a contractor holding an Alberta gasfitter certificate, Class B or Class A, and every contractor in our network agrees in writing to hold the licences Alberta requires.
Expect the technician to test the whole gas train, not just the spot that leaked, and to check the venting and heat exchanger while the furnace is open. A leak on a furnace that is past fifteen winters is often the start of the replacement conversation rather than the end of a repair one.
Why a Calgary winter makes this urgent
From October to April a Calgary house is closed. Windows sealed, doors shut against −25 °C, the furnace and water heater running for hours, and in many homes a gas fireplace in the same basement or the room above. Gas that escapes has nowhere to dilute; it collects, and the concentration climbs toward the range where a spark from a switch or a furnace igniter lights it. In a drafty summer house the same leak would dissipate. In February it does not.
The other winter habit that matters is the attached garage. Warming up a car in a closed or half-open garage attached to the house is how carbon monoxide — not gas, but just as invisible — finds its way into bedrooms. If the smell you notice is in the garage, treat it exactly as you would in the house: out, no ignition, call from outside.
Gas, or something else?
Natural gas is odourized to smell like rotten eggs or sulphur. Three other basement smells get mistaken for it. A dusty, burnt smell on the first cold day of the year is the season's dust burning off the heat exchanger and clears in an hour with a window open. A sharp electrical smell or hot plastic near the furnace is a motor or wiring overheating — switch the furnace off at the wall switch and call a technician, but it is not a gas leak. Sewer gas from a dry floor drain or a failed trap also smells of sulphur; running water into the floor drain will tell you.
If you are not sure, treat it as gas. The cost of being wrong in one direction is a free visit from the utility; the cost of being wrong in the other is the house.
Carbon monoxide is the other emergency
Carbon monoxide has no smell at all. It comes from incomplete combustion — a cracked heat exchanger, a blocked flue, a vent iced over at −30 °C — and it puts headache, dizziness, nausea and drowsiness into a house without any warning a nose can catch. The alarm is the only thing that will tell you. Alberta's building code requires a carbon monoxide alarm in any home with a fuel-burning appliance or an attached garage, inside or within five metres of each bedroom. If yours sounds, the drill is identical to a gas smell: everyone out, no switches, 911 from outside, and no one back in until the fire department has cleared the house.
Questions
Should I open the windows before I leave?
Only if a window is directly on your way out and takes a second. Do not go from room to room opening them, and do not go back in to do it. The utility technician will ventilate the house once the gas is shut off. Leaving fast matters more than airing the house.
Can I turn the gas off at the meter myself?
Only if you already know how, the valve is outside, and you can reach it on your way out without going back in. Otherwise leave it to the utility's technician. The three things that matter are getting out, making no sparks, and calling ATCO Gas from outside.
Does ATCO Gas charge to come out for a gas smell?
Suspected leaks are attended around the clock; the emergency line will tell you what, if anything, applies to your call. The utility's job is to find the leak and make the property safe. What it does not do is repair your appliance; that is a separate visit from a certified gasfitter.
Who repairs the leak after ATCO Gas has been?
A contractor holding an Alberta gasfitter certificate, Class B or Class A. The utility shuts the gas off and may tag the appliance as unsafe; the repair itself — a valve, a connector, a section of line, relighting the furnace and water heater — is trade work. Call us once the house is cleared and our assistant connects you live to a technician from our network whose team holds that certificate.
The smell is faint and comes and goes. Is that still an emergency?
Yes. A faint, intermittent smell is often a small leak at a fitting that gets worse as the furnace cycles and the pressure changes, or a pilot that is going out and relighting. Leave, call ATCO Gas from outside, and let them check. Small leaks in a sealed winter house do not stay small.
Do you repair gas leaks yourselves?
No. hvaclines.ca is a live call-connection service run by PatchLead. Once ATCO Gas has made the house safe, we confirm the problem and your location and connect you on the same call to an independent technician from our network who does the repair and quotes you directly. You pay nothing to use the service.