You can carry out some basic visual and functional checks on your LPG regulator yourself, but any repair, replacement, or work on the gas system beyond the regulator must be done by a licensed gasfitter. If you ever smell gas strongly or suspect a serious leak, act immediately — turn off the cylinder valve, ventilate the area, and call a professional.
What Does an LPG Regulator Do?
Your LPG regulator sits between the gas cylinder and your appliances. Its job is to reduce the high pressure inside the cylinder down to a safe, steady working pressure — typically around 2.75 kPa for most NZ household appliances (confirm the correct pressure for your specific appliances and regulator with the manufacturer or a licensed gasfitter). When it fails, your appliances may not work properly, or worse, gas could escape at unsafe pressures.
Warning Signs Your Regulator May Be Faulty
Before touching anything, make sure you're outdoors or in a well-ventilated area near the cylinder. Look and listen for these common signs:
- Appliances running on low flame or cutting out — burners that won't reach full heat, or a gas hob that keeps going out, can indicate low or inconsistent pressure from a failing regulator.
- Hissing sound from the regulator — a continuous hiss (not from the appliance itself) may indicate gas is escaping through a faulty diaphragm or seal.
- Frost or ice forming on the regulator — some frosting is normal in cold or humid weather, but heavy icing can signal a regulator working too hard or a partially blocked vent.
- Smell of gas near the regulator — a faint LPG smell (like rotten eggs or a strong petroleum odour) near the connection point is a red flag.
- Visible damage — cracks, corrosion, a damaged vent hole, or a cracked body are clear signs the regulator needs replacing.
- Regulator is more than 10 years old — regulators have a finite service life. Check the manufacture date stamped on the body; if it's over a decade old, have it inspected.
The Soapy Water Test
This is the safest DIY leak check you can do:
- Mix a small amount of dish soap with water to make a thick, bubbly solution.
- With the cylinder valve open and an appliance running at low, apply the soapy solution around the regulator inlet connection and the outlet fitting using a brush or cloth.
- Watch for bubbles forming — steady or growing bubbles indicate a gas leak at that joint.
- Turn off the cylinder valve immediately if you see bubbles, and do not use the appliance until the connection has been checked and fixed by a licensed gasfitter.
Never use a naked flame to check for leaks.
Checking Regulator Pressure (For Reference Only)
A proper pressure test requires a manometer (gas pressure gauge) and should be carried out by a licensed gasfitter. However, you can get a rough indication by:
- Turning on a gas hob burner and observing the flame — it should be steady and blue with a small inner cone.
- Turning on multiple appliances at once; if the flame drops significantly, pressure regulation may be failing.
If you want a definitive answer, a gasfitter can test the outlet pressure in minutes with the right equipment.
Common Causes of Regulator Failure
| Cause | What You Might Notice |
|---|---|
| Worn or cracked diaphragm | Inconsistent flame, hissing |
| Blocked vent hole | Icing, erratic pressure |
| Corroded body or fittings | Visible rust, gas smell |
| Loose inlet connection | Bubbles on soapy water test |
| Age-related wear | General poor appliance performance |
What You Can Safely Do Yourself
Under NZ regulations, homeowners are permitted to:
- Connect and disconnect an LPG cylinder to an existing, compliant regulator and hose assembly (e.g., swapping an empty cylinder for a full one).
- Carry out the visual checks and soapy water test described above.
- Replace a complete, pre-assembled LPG hose and regulator set on a portable appliance (such as a BBQ), provided no permanent pipework is involved.
For anything beyond this — including replacing a regulator on a fixed installation, adjusting pressure settings, or repairing any gas pipework — you must use a licensed gasfitter.
When to Call a Professional
Call a licensed gasfitter immediately if you:
- Smell gas and cannot identify the source.
- Find bubbles during the soapy water test.
- Notice a hissing sound from the regulator or pipework.
- Have a regulator that is damaged, corroded, or over 10 years old.
- Experience persistent appliance performance issues after checking the cylinder isn't empty.
Gas work on fixed installations is restricted work under the Gas Act 1992 and must be carried out by a gasfitter registered with the Plumbers, Gasfitters and Drainlayers Board (PGDB). Always ask to see their current practising licence. You can find qualified, local gasfitters on tradedirectory.co.nz.
Safety Reminder
LPG is heavier than air and will pool at ground level, creating a serious fire and explosion risk. Never ignore a gas smell. If in doubt, turn off the cylinder valve, keep people away from the area, and call a professional. For emergencies, call 111. For general gas safety guidance, WorkSafe NZ has helpful resources.
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