Do You Need a Gas Engineer to Replace a Gas Hob?

Replacing a gas hob isn’t like swapping out a broken light switch. One wrong move, and you could be risking a gas leak, fire, or even an explosion. In New Zealand, gas appliances aren’t just a convenience-they’re regulated by law. So, do you need a gas engineer to replace a gas hob? The short answer: yes. Always.

Why Gas Hobs Are Different From Other Appliances

Most kitchen appliances plug into a standard outlet. A faulty toaster? Unplug it. A broken blender? Replace the cord. But a gas hob connects directly to your home’s gas supply line. That line carries pressurized natural gas or LPG-flammable, odorless when pure, and deadly if it leaks. Unlike electrical faults, gas leaks don’t always show warning signs until it’s too late.

Gas hobs have rigid metal pipes, flexible connectors, valves, burners, and pressure regulators. All of these must be installed correctly. A loose joint, a damaged seal, or incorrect gas pressure can lead to incomplete combustion. That means carbon monoxide-a silent killer-could be leaking into your kitchen without you knowing.

Legal Requirements in New Zealand

In New Zealand, the Gas (Safety and Measurement) Regulations 2010 say clearly: only a licensed gasfitter can install, alter, or repair gas appliances. This includes gas hobs. Even if you’re handy with tools, doing this yourself is illegal.

It’s not just about breaking the law. If you install a gas hob without a licensed professional and something goes wrong, your home insurance won’t cover it. Most insurers require proof that gas work was done by a licensed gasfitter. Without that paperwork, you’re on your own if there’s a fire or explosion.

Also, if you sell your home later, buyers will ask for a compliance certificate for all gas installations. Without one, the sale can stall-or fall through entirely.

What a Gas Engineer Actually Does

A licensed gasfitter doesn’t just screw in a new hob. They follow a strict process:

1. Shut off the gas supply at the main valve.
2. Remove the old hob and inspect the gas line for corrosion, damage, or blockages.
3. Check the gas pressure using a manometer to ensure it matches the hob’s requirements (usually 2.75 kPa for natural gas).
4. Install the new hob with certified fittings and seal all joints with gas-rated thread tape or compound.
5. Perform a pressure test on the gas line to detect leaks-often using soapy water or an electronic leak detector.
6. Light the burners and check for even, blue flames. Yellow or orange flames mean poor combustion.
7. Issue a Certificate of Compliance (CoC) for the work.

This isn’t guesswork. It’s science. A gas engineer knows exactly how much torque to apply to fittings, what type of flexible hose to use (and when not to), and how to vent the system properly. Most DIYers don’t have the tools-or the training-to do this safely.

What Happens If You Do It Yourself?

Some people think, “I changed my sink faucet. How hard can a gas hob be?” But gas isn’t water. A small mistake can have deadly consequences.

In 2023, WorkSafe New Zealand reported 17 incidents involving gas appliances in homes, including two fatal carbon monoxide poisonings. All were linked to unlicensed installations or repairs. In one case, a homeowner replaced their hob using a generic flex hose from a hardware store. The hose wasn’t rated for gas pressure. It cracked after six months. The family smelled gas but didn’t know what to do. They called the fire department after passing out from CO exposure.

Even if nothing goes wrong immediately, unlicensed work can cause slow leaks that build up over time. Gas can seep into walls, under floors, or into adjacent rooms. It doesn’t need a spark to ignite-static electricity, a pilot light, or even a light switch can trigger an explosion.

Cost of Hiring a Gas Engineer

Replacing a gas hob with a licensed professional in New Zealand typically costs between $300 and $700. That includes removal of the old hob, installation of the new one, pressure testing, and the Certificate of Compliance.

Compare that to the cost of a gas leak repair: $1,500 minimum. Or a carbon monoxide detector replacement after exposure: $200. Or hospital bills from poisoning: tens of thousands. Or rebuilding your kitchen after a fire: $20,000+.

Some people try to save money by hiring a handyman who says they “know a bit about gas.” But unless they’re a licensed gasfitter (check their license number on the Gasfitter Register), they’re not qualified. And if something goes wrong, you have no legal recourse.

How to Find a Licensed Gas Engineer

Not all plumbers are gasfitters. Not all electricians can touch gas. You need someone with a specific Gasfitter license issued by the New Zealand government.

Here’s how to find one:

• Go to the Gasfitter Register and search by name, location, or license number.
• Ask for their license number and verify it on the register before they start work.
• Only hire someone who offers a Certificate of Compliance after the job.
• Check reviews on TradeMe or Google-look for mentions of gas safety, compliance, and professionalism.
• Avoid anyone who says, “I’ve done dozens of these-no paperwork needed.” That’s a red flag.

Reputable gasfitters will show up with a test kit, a wrench set, thread tape, and a clipboard for the CoC. If they don’t, walk away.

What to Do Before Replacement

Before you buy a new gas hob, make sure:

• Your gas supply type matches the hob’s requirements (natural gas or LPG). They’re not interchangeable.
• The cutout in your benchtop is the right size. Most hobs need 580-610mm width and 490-510mm depth.
• The gas valve behind the hob is accessible. If it’s blocked by a cabinet or wall, the gasfitter may need to relocate it.
• You’re not replacing a gas hob with an electric one unless you’ve had the gas line capped properly.

Buy the hob first, then book the gasfitter. Don’t book the gasfitter first. They’ll need to know the make and model to confirm compatibility and gas pressure settings.

What If Your Hob Just Broke?

If your current hob stops working, don’t assume it’s broken beyond repair. Sometimes it’s just a faulty ignition module or a clogged burner. A gasfitter can diagnose that in under an hour. Replacing the part might cost $80-$150-far less than a full replacement.

Don’t try to fix it yourself. Even cleaning a burner requires shutting off the gas. And if you remove the hob without turning off the supply, you risk a leak.

Final Check: Is It Worth the Risk?

Think about this: Would you let an unlicensed electrician rewire your house? Would you let someone without a medical license perform surgery? Gas is just as dangerous. It doesn’t care how good your YouTube tutorials are. It doesn’t care if you’ve watched five videos on YouTube. It only cares if the joint is sealed, the pressure is right, and the ventilation is adequate.

Replacing a gas hob isn’t a DIY project. It’s a safety-critical task. The cost of hiring a gas engineer is small compared to the cost of a mistake. And in New Zealand, it’s not optional-it’s the law.

When it comes to gas, there’s no shortcut. Only one path: a licensed professional, a Certificate of Compliance, and peace of mind.