A leaking gas bayonet point is a serious safety hazard, but there is a simple, safe check you can do yourself before calling a professional. If you ever smell gas strongly or suspect a significant leak, do not attempt any checks — leave the area, shut off the gas at the meter, and call your gas supplier or 111 immediately.
What Is a Gas Bayonet Point?
A gas bayonet fitting (sometimes called a bayonet socket or gas outlet) is a quick-connect point installed on an exterior wall or post, allowing you to plug in a compatible gas appliance — such as a barbecue or patio heater — without using a flexible hose and regulator. The fitting has a spring-loaded valve that opens only when a bayonet plug is inserted. Outdoor bayonet points are exposed to the elements, which can cause wear on seals and connections over time.
Before You Start: Safety First
Gas leaks can be invisible and odourless in small quantities (though LPG and natural gas are odourised for detection). Always follow these precautions:
- Never use a naked flame (lighter, match, candle) to check for a gas leak.
- Work in a well-ventilated outdoor area — bayonet points are outdoors, which helps, but avoid enclosed spaces like garages.
- Keep ignition sources (cigarettes, power tools, switches) well away.
- If you smell a strong gas odour at any point, stop immediately, move away, and call your gas supplier.
- Check your gas supplier's emergency line — for natural gas this is often Vector (0800 800 800 in Auckland) or your regional network operator; for LPG, contact your cylinder supplier.
For more on gas safety in the home, WorkSafe NZ has useful guidance.
The Soapy Water Test
The most reliable DIY method for detecting a small gas leak is the soapy water bubble test. Here's how to do it:
What You'll Need
- A small bowl or spray bottle
- Dishwashing liquid and water (a generous squeeze of detergent in about 250 ml of water)
- A soft paintbrush or sponge
- A torch (for seeing clearly)
Step-by-Step
- Make sure an appliance is connected — the bayonet valve only opens when a plug is inserted. With nothing connected and the valve closed, there is nothing to test. Connect your barbecue or another compatible appliance, or use a blanking plug if you have one.
- Turn on the gas at the meter or cylinder valve so gas is present in the line.
- Do not ignite the appliance — keep it switched off at the appliance.
- Mix your soapy solution and apply it generously around the entire bayonet fitting: the joint where the fitting meets the wall or pipe, the collar where the plug connects, and any visible pipework nearby.
- Watch for bubbles — even slow, steady bubbling indicates escaping gas. A leak will produce continuous bubbles, not just a single burst from air displacement.
- Check all around the fitting, including underneath and at the back if accessible.
- If no bubbles appear after 30–60 seconds, the fitting is likely sound. Turn off the gas at the meter when you're done.
What If You Find Bubbles?
If you see bubbles, turn off the gas at the meter or cylinder immediately and do not use the fitting. This is not a DIY repair — see the section below on calling a professional.
Other Signs of a Leaking Bayonet Point
Beyond the soapy water test, watch for these indicators:
| Sign | What It May Mean |
|---|---|
| Smell of rotten eggs or mercaptan near the fitting | Gas is escaping |
| Dead or yellowing grass/plants directly around the fitting | Underground gas leak nearby |
| Hissing sound at the fitting | Active gas escape |
| Appliance won't light or has low flame | Possible leak reducing pressure |
| Visible corrosion or cracked fittings | Seal or fitting failure |
Checking the Condition of the Fitting
While you're inspecting, look for:
- Corrosion or rust on the fitting body or surrounding pipework
- Cracked or perished rubber seals visible at the connection point
- Loose or wobbly fitting where it enters the wall
- Damage from UV exposure, lawn mowers, or impact
Outdoor fittings should comply with the NZ Building Code and relevant gas installation standards. If your fitting looks physically damaged or is more than 10–15 years old, it's worth having a licensed gasfitter inspect it regardless of whether you find a leak.
When to Call a Professional
Under New Zealand law, all gas fitting work is restricted work and must be carried out by a licensed gasfitter registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB). This includes:
- Repairing or replacing a leaking bayonet fitting
- Relocating or installing a new bayonet point
- Any work on gas pipework, valves, or connections
As a homeowner, you may only perform the visual and soapy water checks described above — you cannot legally repair or alter the gas installation yourself, even if the fix seems simple.
If you find a leak, or if you're unsure about the condition of your fitting, find a qualified local gasfitter on tradedirectory.co.nz. A licensed gasfitter can also issue a Certificate of Compliance for any work completed, which is important for insurance and future property sales.
Certifying Plumber
