Do Plumbers Change Boilers? What You Need to Know Before Calling a Pro

When your boiler breaks down in the middle of winter, you don’t have time to figure out who to call. You just need heat. So you Google ‘plumbers change boilers’-and suddenly you’re stuck between a plumber, a heating engineer, and a random guy on Facebook Marketplace who says he’ll fix anything. Here’s the truth: plumbers can change boilers, but not all of them should be the ones you hire.

Not All Plumbers Are Created Equal

Plumbing and boiler work used to go hand-in-hand. Back in the day, plumbers installed and fixed everything from taps to radiators. Today? It’s way more complicated. Modern boilers aren’t just hot water tanks-they’re complex gas-fired systems with electronic controls, pressure sensors, flue systems, and safety certifications. In Australia, if a boiler runs on natural gas or LPG, it’s regulated under the Gas Safety Act. That means only licensed gas fitters can legally connect or modify gas lines.

Many plumbers are qualified to work on water pipes, radiators, and towel rails. But if they don’t hold a Gas Fitter’s License (Class 2 or higher in South Australia), they can’t touch the gas side of your boiler. And if they do, you’re risking gas leaks, carbon monoxide poisoning, or voiding your home insurance. A plumber without gas certification might be great at fixing a leaky pipe under the sink-but they shouldn’t be installing your new Vaillant or Worcester Bosch boiler.

Who Actually Installs Boilers in Australia?

The right person to call is a Gas Heating Engineer or Qualified Boiler Technician. These professionals hold:

• A current gas fitter’s license (issued by the South Australian Energy and Water Ombudsman or equivalent state body)
• Specific training on boiler models (like Worcester, Ideal, or Baxi)
• Registration with the Australian Gas Association (AGA) or similar bodies
• Public liability insurance that covers boiler installations

Some plumbers have dual qualifications-they’re both plumbers and gas fitters. That’s ideal. But you can’t assume. Always ask: “Are you licensed to work on gas appliances?” and ask to see their license number. You can verify it online through the SA Energy and Water Ombudsman website.

Most boiler manufacturers require installation by a certified technician to keep the warranty valid. If a plumber without gas certification installs your boiler, your 10-year warranty could be thrown out the moment you need a claim. That’s not a risk worth taking.

What’s Involved in Changing a Boiler?

Changing a boiler isn’t like swapping a lightbulb. It’s a full system job. Here’s what a qualified technician actually does:

1. Turns off gas and water supply
2. Drains the central heating system
3. Removes the old boiler and disposes of it properly
4. Checks flue and venting for compliance
5. Installs new boiler with correct gas pressure settings
6. Connects to existing pipework and electrical supply
7. Performs a leak test and combustion analysis
8. Issues a Gas Installation Certificate (required by law)
9. Explains how to use the controls and maintenance schedule

That’s nine steps-and only one of them involves pipes. The rest? Gas, electrical, safety, and compliance. A plumber who’s never touched a gas boiler might handle the water lines, but they won’t know how to set the gas pressure to 20 mbar or interpret the flue gas readings. That’s where things go wrong.

When a Plumber Can Help (And When They Can’t)

There are times when a plumber is exactly who you need:

• Replacing a broken pipe connected to the boiler
• Fixing a leaky radiator or towel rail
• Installing new underfloor heating pipes
• Adding extra radiators to your system

But if you’re replacing the boiler itself? That’s not plumbing. That’s gas engineering. Think of it like this: a mechanic can change your tires. But if your car’s engine is failing, you need a specialist with diagnostic tools and factory training.

Some companies offer full-service boiler replacement with plumbers and gas fitters working together. That’s fine-as long as the gas work is done by the licensed technician. Don’t let the plumber take the credit for the gas installation.

Red Flags When Hiring Someone to Replace Your Boiler

Watch out for these warning signs:

• They won’t show you their gas license
• They say, “I’ve done dozens of these” without naming a certification
• They quote a price that’s way lower than others (usually means they’re cutting corners on safety checks)
• They don’t offer a Gas Installation Certificate
• They suggest bypassing the flue or using an old vent
• They refuse to explain how the boiler’s controls work

Boiler installation isn’t a job you want to DIY-or hire someone half-qualified for. A single mistake can lead to carbon monoxide buildup, which kills about 10 people in Australia every year, according to the Australian Institute of Health and Welfare. That’s not a statistic you ignore.

What to Look for in a Boiler Installer

Here’s what to ask before signing anything:

• Can you show me your current gas fitter’s license? (Ask for the number and verify it online)
• Are you certified by the boiler manufacturer? (Worcester, Ideal, Viessmann all have accredited installers)
• Do you provide a Gas Installation Certificate? (This is legally required)
• Do you include a system flush and inhibitor treatment? (Prevents sludge buildup in new boilers)
• What’s the warranty on labor? (Most reputable companies offer 1-2 years)
• Will you test for carbon monoxide after installation?

Ask for references. Call past customers. Check Google reviews-not just the 5-star ones. Look for comments about communication, cleanliness, and whether the technician explained everything clearly.

Cost of Replacing a Boiler in Adelaide (2025)

A standard gas boiler replacement in Adelaide ranges from $3,500 to $6,500, depending on:

• Boiler type (combi, system, or regular)
• Brand (Worcester Bosch, Vaillant, Baxi, or cheaper imports)
• Complexity of the install (e.g., moving the boiler location, upgrading flue, electrical rewiring)
• Whether you need a system flush or new radiators

Don’t fall for the $2,000 boiler special. That’s usually a low-quality unit installed by someone cutting corners. A good combi boiler from a trusted brand, installed properly, will last 12-15 years. Cheap installs often fail in 3-5 years.

What Happens If You Use the Wrong Person?

You might think you saved money. But here’s what can go wrong:

• Your boiler develops a gas leak-silent, deadly, and undetectable without proper testing
• The flue is blocked, causing carbon monoxide to back up into your home
• Your insurance denies a claim because the installer wasn’t licensed
• The boiler fails within months and the manufacturer won’t honor the warranty
• You’re fined by the local council for unlicensed gas work

In South Australia, unlicensed gas work is a criminal offense under the Gas Safety Act 2018. Fines can reach $10,000. And if someone gets sick because of it? The penalties get much worse.

Bottom Line: Plumbers Can Change Boilers-But Only If They’re Also Gas Fitters

Yes, plumbers can change boilers. But only if they’re licensed gas fitters first. Don’t assume. Don’t guess. Always ask for proof of gas certification. If they can’t show it, walk away. Your safety and your home’s heating system aren’t worth risking on a guess.

When in doubt, call a company that specializes in boiler replacement-not one that does everything from leaky taps to oven repairs. Look for “Boiler Installation Specialists” in your area. They know the codes, they use the right tools, and they don’t cut corners on safety.

Boilers keep you alive in winter. Make sure the person installing yours knows how to do it right.