That rotten-egg smell is not the gas. Natural gas has no smell of its own at all, so an odourant is deliberately added to it, a sulphur compound called mercaptan, purely so that your nose finds a leak before anything with a spark in it does. If you can smell it, the safety system is working exactly as designed and you have a few minutes to spend well.
Here is what to do with them, in order, and what not to touch on the way past. One thing reorders the list for most people reading this in Parramatta: in an apartment, your gas meter is not inside your home, and under the network's own rules it is not allowed to be. That is section 8. If the smell is strong right now, stop reading, get everyone out and ring 000.
Do not touch a light switch, a power point or your phone while you are still inside. Turn the appliance off if you are standing next to it, open doors and windows on the way past, get everyone out, and make the call from outside: Jemena on 131 909 for a gas leak, or 000 if the smell is strong, if anyone feels unwell, or if it is in a shared part of a building. In most Parramatta homes the meter sits in a common meter bank rather than in the unit, so turning it off yourself is often not an option, and knowing that in advance saves you the two minutes you would waste looking.
- No switches, no phone, no flames, no cigarettes
- Turn the appliance off if it is at arm's length
- Open doors and windows on the way out
- Turn the gas off at the meter only if you can reach it safely
- Get everyone out and stay out
- Ring 131 909 from outside, or 000 if it is strong
- Leave it off until a licensed gas fitter has tested it
On this page
- Do not touch a switch or your phone
- Turn the appliance off if you are there
- Open the doors and windows
- Turn it off at the meter, if you can
- Get everyone out and stay out
- Ring from outside
- Leave it off until it is tested
- Why the meter trick fails in local flats
- Whose pipe is it in a strata block
- What actually leaks around here
- Six things that make it worse
- Carbon monoxide, the one you cannot smell
- When it is a 000 call
1. Do not touch a switch, a power point or your phone
This is the one that catches people, because the instinct when something is wrong is to turn something off. A switch makes a small arc every time it moves, and it does that whether you are switching on or switching off. So does a power point, a doorbell, a garage remote, a rangehood and the phone in your hand.
Jemena, which owns and operates the gas distribution network your street is connected to, puts it plainly: remove or turn off ignition sources and leave the area immediately, do not smoke or use your phone, and put out any naked flames. NSW Government's consumer gas safety guidance adds the same instruction from the other direction, to extinguish all naked flames and make sure cigarettes are not lit.
If a light is already on, leave it on. If it is off, leave it off. Same for the aircon, the extraction fan and the TV. The only thing worth touching is a gas control, and only if you are already standing at it.
2. Turn the appliance off if you are standing next to it
Most household gas smells come from an appliance rather than from a pipe. A cooktop knob nudged a quarter turn by a tea towel. A burner blown out by a rangehood running on full. A heater whose pilot has dropped out and is quietly letting gas past. Queensland's state gas safety guidance sets the same order that works here: do not light anything or switch anything on or off, turn the gas appliance off, open doors and windows, and then turn the supply off if the smell persists.
In a Parramatta apartment the search list is short and Jemena publishes it: the four gas things it expects to meter in a local flat are cooking facilities, an internal bayonet point for heating, an external bayonet point for the barbecue, and an instantaneous hot water system. In a one or two bedroom unit you can usually see most of that from the doorway.
If the control is at arm's length, turn it off. If you would have to go hunting through the house for it, do not. Getting out is worth more than finding the source, and finding the source is our job.
3. Open the doors and windows on your way past
NSW Government's guidance is to open all doors and windows for ventilation. Do it on the way out, not as a project. Which openings actually help depends on what is leaking, and that is worth thirty seconds of your attention, because the two gases in a normal Parramatta home behave in opposite ways.
Natural gas rises. The NSW Rural Fire Service's own flammable gas guidance describes it as lighter than air, rising and dispersing, and Queensland's puts it the same way: natural gas is lighter than air and a leak will tend to rise and may disperse in open atmosphere. So it gathers at the ceiling, in the top of a cupboard, and up a stairwell. High windows and awning sashes matter more than the bottom half of a sliding door.
The bottle on the balcony does the exact opposite. The same two sources describe LPG as heavier than air, settling in low places and pooling in low areas and drains. A leaking barbecue bottle does not go up and out of an open window. It sits on the balcony floor at ankle height and runs downhill, into a stairwell or a floor drain. In a suburb where the barbecue is on a balcony rather than in a back yard, that difference is not academic.
4. Turn the gas off at the meter, only if you can reach it safely
Jemena's instruction is that if you have to evacuate and it is safe to do so, you should turn off your gas supply or gas bottles, and that the valve to do it is on the side of your meter or on top of the bottle.
On a freestanding house around Northmead, Oatlands, Winston Hills or the older parts of North Parramatta, that usually means a meter box on the side or front wall with a valve on the pipe beside the meter. It is a quarter turn, so the handle finishes sitting across the pipe rather than along it. Use your hand, not a shifter. If it will not move, leave it and get out.
In an apartment it usually means you cannot, and that is a rule rather than bad luck. Section 8 explains why. Either way, the meter is not yours to open up: Jemena's own network documentation states that meter equipment is, and remains, the property of Jemena NSW Gas Networks. Turn the valve or leave it alone. Nothing else.
5. Get everyone out, and stay out
NSW Government guidance is blunt on this and it deserves quoting rather than paraphrasing: always treat any gas leak as a potential lethal risk, and if you smell gas in your property, exit the building immediately, call 000 and ask for the NSW Fire Service.
For most people reading this, getting out does not mean a front door and a lawn. Six Parramatta homes in seven are in a block, so it means a corridor, a fire stair and a footpath, and the gas you are walking away from is rising up that same stairwell ahead of you.
In a block, take the stairs rather than the lift. A lift is a sealed box full of electrical contacts and it is the last place you want to be if the power drops. Knock on a neighbour's door on the way past only if it does not slow you down, and get well clear of the building rather than standing in the lobby.
6. Ring from outside, not from the kitchen
Once you are out and clear, make the call. Gas faults go to the network operator, not to the company that sends you the bill. The Australian Energy Market Commission's pipeline register records the NSW gas network as a distribution pipeline owned and operated by Jemena Gas Networks (NSW) Ltd, and it is Jemena, not your retailer, that has crews and can shut a street main. The number is 131 909, answered any time of day, seven days a week. NSW Government guidance also notes your supplier's number is on your gas bill if you are unsure who you are with.
Ring 000 instead, and ask for Fire and Rescue NSW, if the smell is strong, if anyone feels dizzy or unwell, if you can hear gas escaping, or if the smell is in a shared corridor, stairwell or car park where you have no idea how many homes are affected.
Gas made safe, then found and fixed
Once the network has made the street safe, someone still has to find the leak and certify the repair. That part is ours, 24/7.
7. Leave it off until a licensed gas fitter has tested it
Do not relight anything, and do not turn the supply back on to see whether the smell has gone. If a pilot went out because a valve is passing, relighting it lights a leak.
In NSW you need a licence or certificate to do any plumbing, draining or gasfitting work regardless of the cost of the work or whether the work is residential, commercial or industrial. The penalty for doing it unlicensed is $22,000 for an individual and $110,000 for a company. There is no small-job carve-out for gas the way there is for swapping a tap washer, which we cover in our guide on what you can legally fix yourself in NSW.
Afterwards, ask for the paperwork. Gasfitting sits under the Gas and Electricity (Consumer Safety) Act 2017 and its 2018 Regulation, AS/NZS 5601:2022 is legally enforced for gas installations and appliances in NSW, and for a network-connected installation the gas fitter must test for defects and lodge a Certificate of Compliance within 5 business days. Since 1 March 2026 that has to go through the Building Commission NSW eCert portal, and emailed or PDF certificates are no longer accepted. Our gas fitting licence number, 368473C, goes on every job.
8. Why the meter trick does not work in most Parramatta homes
Almost every gas safety article on the internet tells you to go and turn the meter off. For most people in this suburb, that advice is simply not actionable, and it is worth knowing that on a calm Tuesday rather than discovering it at 11pm.
The 2021 Census counted 14,220 private dwellings in Parramatta. Of the occupied ones, 85.6% are flats or apartments, 10,062 of them. Separate houses are 7.7%, or 903 dwellings. Roughly six homes in seven here are in a block.
Jemena's design guide for medium density and high rise residential buildings sets out where the meters for those homes go. Apartment gas meters, it says, must be located within common areas of the development, and may be installed individually or in groups at a central location. Then it states the part that matters to you: the location of individual apartment meters within dwellings is not permitted.
So your meter is in a bank on a wall in a meter room, a car park or a cupboard off the lobby, roughly 450mm tall and 250mm wide with a clear 100mm around it, tagged with your unit number, and mounted no higher than 2.2 metres off the floor. It is behind a door you may not have a key to. That is not your building cutting corners; it is the network's standard.
Find out which room your block's gas meter bank is in, and whether residents can get into it. Ask building management or your strata manager if it is not obvious. Two minutes now decides whether step four above is available to you at all, and there is no worse time to learn the answer than while you are trying to leave.
9. The other thing an apartment changes: whose pipe is it
Jemena divides a building's gas into two halves, and the boundary between them is your meter. Everything upstream is what it calls primary reticulation: a shared service to supply all apartments within the building, running as risers up through the block. Everything downstream is secondary reticulation, typically 15mm to 25mm, dedicated to your apartment and feeding only your appliances.
That line matters because it sorts a smell into two very different problems. A smell inside your unit, at the cooktop or the heater bayonet, is on your side of the meter. A smell in a corridor, a stairwell or the car park is far more likely to be on the shared side, which makes it the building's problem and potentially everyone's.
This is a Parramatta question far more than it is a Sydney one. With 10,062 of the suburb's occupied dwellings being flats against 903 separate houses, the shared riser is the normal case here and the private gas service running under a front lawn is the exception.
Who then pays is murkier than most people expect. The NSW model common property memorandum, the document that settles maintenance responsibility in a strata scheme that has adopted it, lists Plumbing and Electrical in both the owners corporation and lot owner columns and does not mention gas anywhere at all. What it does say is that a stove and a hot water service exclusive to a single lot are the lot owner's, and pipes within a common property wall, floor or ceiling are the owners corporation's. Past that, your scheme's by-laws and the strata plan decide it. Get the answer in writing before anyone commits to paying for anything.
10. What actually leaks around here
Jemena's own guide lists the gas appliances it expects to meter in a local apartment: cooking facilities, internal bayonet points for heating, external bayonet points for barbecues, and instantaneous hot water systems. That is a short and useful list of the four things to think about when the smell starts.
The bayonet nobody has plugged anything into. Building Commission NSW published an advisory note on bayonet connection point location because its audits of Class 2 buildings, which is what most of Parramatta's housing stock is, found gas connection points for hose assemblies frequently installed in a non-compliant location. An unused bayonet is a hole in your gas system held shut by a spring-loaded cover, and it is worth knowing where yours are.
Pipework that was never properly clipped. A separate Building Commission advisory note exists because gas audits of Class 1 and 2 buildings found piping not adequately supported in gas installations, against clause 5.8.1 of AS/NZS 5601.1:2022, which requires supports that firmly restrain the piping in the intended position, and the spacing table in clause 5.8.2. Pipe that is free to move works its own joints loose over years.
A shovel. Jemena asks you to contact Before You Dig Australia at least two working days before you excavate, and they are open weekdays. A new fence, a deck footing, a raised bed: your gas service runs under the same front yard as everything else on the property. This is the one on the list you can prevent entirely with a free phone call.
And the boring one. A knob turned by a tea towel, a pot that boiled over and drowned a burner, a heater pilot that dropped out overnight. Unglamorous, and more common than all the rest put together.
11. Six things that make it worse
- Ringing your retailer. They sell you the gas and send the bill. Jemena runs the pipe and the meter, and 131 909 is answered around the clock.
- Turning a light off. Exactly the same arc as turning it on. If it is on, leave it on.
- Airing it out and going to bed. Ventilation buys time against a leak that has stopped. Against one that is still running, it just delays the point at which the room fills again, and in an apartment the gas has nowhere to go but up into the ceiling space and out into the corridor.
- Relighting the pilot to see if it holds. If the pilot went out because something upstream is passing gas, you have just put a flame on it.
- Waiting for the strata meeting. If the smell is on the shared side of the meter in a Parramatta block, it is the owners corporation's to fix, but nothing about that makes it wait. Ring 131 909 first and raise it with the committee afterwards.
- Getting a handy mate to have a look. $22,000 for an individual doing unlicensed gasfitting work, and an insurer that will ask who did it.
12. Carbon monoxide: the leak your nose cannot find
Everything above depends on smelling something. Carbon monoxide is the case where you will not. NSW Health describes it as a poisonous gas that you cannot see, taste or smell, and lists the warning signs as headache, nausea, vomiting and weakness, running through to dizziness, fainting and loss of consciousness. It advises never using an unflued gas heater overnight in the room where you sleep. If you suspect exposure, the Poisons Information Centre is on 13 11 26, 24 hours a day.
The version of this that is peculiar to Parramatta is a renovation, not an appliance. In 2026 Building Commission NSW issued an advisory note warning that a serious risk of carbon monoxide poisoning can arise when a gas appliance certified and installed for external operation is enclosed by subsequent building works, and it names the exact thing that happens in this suburb: glazing, windows, screens or other enclosure elements added to balconies and verandahs that contain gas appliances, restricting the ventilation the appliance was certified to have. An instantaneous gas hot water unit on a balcony is an ordinary arrangement in a Parramatta block, and enclosing that balcony to win back a usable room is an ordinary Parramatta renovation. The note's instruction is to consult a licensed gas fitter before that work, not after it.
The tell is behavioural rather than olfactory. If nobody can smell a thing but everyone gets a headache in the same room, and it lifts when they leave the house, stop looking for a gas leak and start looking at what is burning in there. Our guide on what to check when there is no hot water covers the pilot and supply side of a gas unit if that is where this started.
13. When it is a 000 call, and when it can wait
Ring 000 now if the smell is strong, if anyone feels dizzy, sick or confused, if you can hear gas escaping, or if the smell is in a common corridor, stairwell or car park where you cannot tell how many homes are involved. Do not weigh it up. Get out and ring.
Ring 131 909 from outside if you can definitely smell gas, it is faint rather than overwhelming, everyone is fine, and you are already out of the building. Jemena will come and make it safe.
It is probably nothing if you get a brief whiff at the cooktop as a burner lights and it is gone within seconds. That is the small puff of unburnt gas before ignition, and it is normal. What is not normal is a smell that lingers after every burner is off, or one that comes back in the same spot day after day. That is a leak and it will not improve on its own.
And the one worth saying honestly, because it saves people a call-out fee: a rotten-egg smell in a bathroom with no gas appliance in it is far more often a dried-out floor waste trap letting sewer air back into the room than a gas leak. Run water down every drain in there and see whether it clears. If you are not sure which one you have, treat it as gas. Getting that wrong in the safe direction costs you an hour standing on the footpath. Getting it wrong the other way costs considerably more.
- Nothing that arcs: no switches either way, no power points, no phone until you are outside.
- Turn the appliance off only if you are already standing at it, open up on the way past, and get everyone out.
- In roughly six Parramatta homes out of seven the gas meter is in a common bank, not in the unit, because the network does not permit it inside a dwelling. Find out today which room yours is in.
- Natural gas rises to the ceiling. The barbecue bottle on the balcony does the opposite and pools at floor level.
- 131 909 for a gas leak, 000 if it is strong, anyone is unwell, or it is in a shared part of the building.
- Nothing gets relit until a licensed gas fitter has tested it and lodged the certificate. Ask for the licence number; ours is 368473C.
Gas smell FAQs
I live in a Parramatta apartment. Where is my gas meter, and can I turn it off myself?
Almost certainly not from inside your unit, and that is a network rule rather than a quirk of your building. Jemena's design guide for medium density and high rise residential says apartment gas meters must be located within common areas of the development, that they may be grouped at a central location, and that the location of individual apartment meters within dwellings is not permitted. So your meter sits in a bank in a meter room, a car park or a cupboard off the lobby, tagged with your unit number, and you may not have a key. Go and find out which room it is in before you ever need it, because that answer decides whether step four is yours or not.
I can smell gas in the corridor of my block, not in my unit. Is that my problem?
Treat it as urgent and treat it as everyone's. Jemena splits an apartment building's gas into two parts: the primary reticulation, which it describes as a shared service to supply all apartments within the building, running as risers through the block upstream of the meters, and the secondary reticulation downstream of your own meter, typically 15mm to 25mm, which serves only your unit. A smell in a corridor, stairwell or car park is on the shared side of that line far more often than not. Get out, ring 131 909 from outside, and tell building management as well so the owners corporation is on notice.
Do I ring Jemena or my energy retailer?
Jemena. Your retailer sells you the gas and sends the bill; Jemena owns and operates the distribution network the gas actually travels through, and it is the one with crews. The number is 131 909, staffed around the clock. If the situation is worse than a phone call, 000 comes first and Jemena second.
We are glazing in the balcony. The gas hot water unit is out there. Does that matter?
Yes, and it is the exact scenario Building Commission NSW wrote an advisory note about in 2026. It warns that a serious risk of carbon monoxide poisoning can arise when a gas appliance certified and installed for external operation is enclosed by subsequent building works, and it names glazing, windows and screens added to balconies and verandahs that contain gas appliances. An instantaneous gas hot water unit on a balcony is an ordinary Parramatta arrangement and enclosing that balcony is an ordinary Parramatta renovation, which is why the two collide here more than most places. Talk to a licensed gas fitter before the work, not after.
The smell is in the bathroom and there is no gas appliance in there. Is it a leak?
Probably not. A floor waste or a rarely used shower drain whose trap has dried out will let sewer air back into the room, and that reads as rotten eggs to most noses, same as the odourant in gas. Run water down every drain in the room and see whether it clears over a day. That said, the cost of being wrong is not symmetrical: if you are unsure, treat it as gas, get out and ring. Nobody has ever regretted that order of operations.
What paperwork should I get after a gas fitter has been?
A certificate. Gasfitting in NSW sits under the Gas and Electricity (Consumer Safety) Act 2017 and its 2018 Regulation, and for a network connected installation the gas fitter must test the installation for defects and lodge a Certificate of Compliance within 5 business days. Since 1 March 2026 that has to go through the BCNSW eCert portal, and emailed or PDF submissions are no longer accepted. Ask for the licence number too. Ours is 368473C.