Smelling gas in your home is something you should never ignore. Whether you're on natural gas or LPG, a gas leak can be dangerous — even life-threatening — if not handled quickly and correctly. Here's exactly what to do, what causes gas smells, and how to stay safe.
Act Immediately: Your First Steps
If you smell gas, follow these steps right away — do not delay:
- Don't touch any switches or appliances. Do not turn lights on or off, use your phone inside, or operate any electrical device. A spark could ignite the gas.
- Extinguish any open flames. Candles, cigarettes, and pilot lights should be put out if you can do so safely without using electrical ignition.
- Open windows and doors to ventilate the space.
- Turn off the gas at the meter or LPG cylinder if it is safe and accessible to do so. The isolation valve is usually a lever or tap — turn it so it sits across (perpendicular to) the pipe to shut off the flow.
- Get everyone out of the building, including pets.
- Call for help from outside or a neighbour's phone. In an emergency, call 111. For gas network emergencies (natural gas), contact your gas distributor — in most of NZ this is First Gas on their 24-hour faults line.
- Do not re-enter until a licensed gasfitter or emergency services have declared it safe.
⚠️ Safety note: Never use a lighter or match to try to find a leak. Do not assume the smell will go away on its own.
What Does a Gas Leak Smell Like?
Natural gas and LPG are both naturally odourless, but gas suppliers add a chemical called mercaptan to give them a distinctive smell — often described as rotten eggs or a strong sulphur odour. Even a faint whiff should be taken seriously. If you notice the smell near an appliance, a pipe connection, or your meter, there's a good chance you have a leak somewhere in the system.
Common Causes of Gas Smells in NZ Homes
Understanding what might be causing the smell can help you communicate clearly with a gasfitter, but diagnosing and repairing gas leaks is restricted work — more on that below.
- Faulty or aging appliance connections: Flexible hoses connecting cooktops, heaters, or hot water systems can crack or loosen over time.
- Corroded or damaged pipework: Older homes may have pipework that has deteriorated, especially if it runs through areas exposed to moisture.
- Poorly fitted appliances: DIY installation or work done by an unqualified person is a common culprit.
- Pilot light issues: A pilot light that has blown out on an older appliance can release unburned gas.
- LPG cylinder connections: On LPG systems, the regulator, hose, or cylinder valve can develop leaks, particularly if equipment is old or has been knocked.
- Seismic movement: In earthquake-prone NZ, ground movement can stress gas connections and fittings.
What You Can Safely Check (and What You Cannot)
As a homeowner, there are very limited things you should do yourself when it comes to gas:
You may safely:
- Turn off the gas supply at the meter or cylinder isolation valve
- Ventilate the area by opening windows and doors
- Check whether a pilot light has simply gone out (once the area is ventilated and you are certain there is no ongoing leak)
You must NOT attempt to:
- Repair, modify, or reconnect any gas pipework or fittings
- Reconnect or install gas appliances
- Test for leaks using anything other than approved leak detection spray (and even then, leave repairs to a professional)
Why Is Gas Work Restricted?
Under New Zealand law, gasfitting work is restricted work that must be carried out by a licensed gasfitter registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB). This includes installing, repairing, altering, or certifying any gas installation. Doing this work yourself — or hiring an unlicensed person — is illegal and extremely dangerous. Always ask to see a tradesperson's current licence before work begins.
Checking Your Appliances After the All-Clear
Once a licensed gasfitter has inspected your home and confirmed it is safe, they will identify the source of the leak and carry out any necessary repairs. They will also issue a Certificate of Compliance for any restricted work completed, which is an important document to keep for your records and may be required if you sell your home.
Regular appliance servicing is the best way to prevent gas leaks. Most manufacturers and gasfitters recommend having gas appliances — heaters, cooktops, hot water systems — serviced every one to two years. This is especially important for older appliances or those that run continuously.
When to Call a Professional
You should call a licensed gasfitter any time you:
- Smell gas, even faintly or intermittently
- Notice a hissing sound near a gas pipe or appliance
- Have a gas appliance that won't stay lit or keeps cutting out
- Are moving, replacing, or installing any gas appliance
- Haven't had your gas system serviced in several years
- Are buying or selling a home with gas appliances
For urgent situations, call 111 first. For non-emergency gasfitting work, you can find qualified, licensed gasfitters in your area at tradedirectory.co.nz.