Boiler Cost Calculator
Boiler Replacement Cost Calculator
Cost Breakdown
Quick Tips
- Get 3 quotes before deciding
- Always ask for a written breakdown
- Don't skip system flushing
- Consider smart thermostats for savings
- Winter is the best time to book installation
When your boiler starts making strange noises, leaking water, or just won’t heat up anymore, the first question that pops up isn’t about repair-it’s about replacement. How much does a new boiler cost? It’s not a simple number. A basic model might set you back $1,800. A high-efficiency one with smart controls could hit $5,500. And that’s before installation. In Adelaide, where winters get chilly and gas prices are still climbing, knowing what you’re paying for isn’t just smart-it’s essential.
What’s Actually in the Price?
A new boiler isn’t like buying a toaster. You’re not just paying for the machine. You’re paying for the unit itself, the labor to install it, the flue system, the controls, the water pressure checks, and the safety certifications. Most homeowners think the boiler’s price tag is the total cost. It’s not. Installation can add 30% to 50% to the final bill. A Worcester Bosch Greenstar iSystem might cost $2,200, but with certified gas fitting, system flushing, and thermostat setup, you’re looking at $4,100-$4,800 installed.
Some companies quote you $1,500 for a boiler and then add $1,200 for "hidden" extras like condensate pipe extensions, radiator balancing, or flue repositioning. Ask for a full breakdown. If they won’t give you one, walk away.
Boiler Types and Their Price Ranges
There are three main types of boilers in Australia: combi, system, and regular. Each serves different homes and has different costs.
| Boiler Type | Best For | Unit Cost | Installed Cost Range |
|---|---|---|---|
| Combi Boiler | Small to medium homes (1-3 bedrooms) | $1,600-$2,500 | $3,200-$4,500 |
| System Boiler | Medium to large homes with multiple bathrooms | $2,000-$3,200 | $3,800-$5,200 |
| Regular Boiler | Older homes with existing tanks and cylinders | $1,800-$2,800 | $4,000-$5,800 |
Combi boilers are the most popular in Adelaide. They heat water on demand, so you don’t need a hot water tank. That saves space and reduces energy waste. If you live in a unit or a small house, this is your best bet. System boilers need a separate hot water cylinder but offer better flow rates for homes with two or more bathrooms. Regular boilers are mostly found in older homes built before 2000-they need a cold water tank in the loft and a hot water cylinder. They’re more expensive to install because of the extra plumbing.
Brands That Actually Deliver Value
Not all boilers are created equal. Some brands cut corners on parts or service networks. In Adelaide, you want a brand with local technicians who actually show up when you call.
- Worcester Bosch: Reliable, quiet, and backed by a strong Australian service network. Their Greenstar range is the most common replacement choice.
- Viessmann: German-engineered, high efficiency, and built to last. More expensive upfront, but often pays for itself in lower gas bills over time.
- Vaillant: Good balance of price and performance. Popular in newer builds. Easy to service.
- Alpha: Budget-friendly without being cheap. Solid for renters or short-term homeowners.
Avoid no-name brands sold online or at big-box stores. They might look cheaper, but if something breaks, you’ll be stuck waiting weeks for a part-or worse, paying twice for a replacement that fails again.
What Adds to the Cost?
Here’s what can spike your bill if you’re not careful:
- Flue rerouting: If your old boiler was on an internal wall and the new one needs to go outside, you’re looking at $400-$800 extra for a new flue pipe and weatherproofing.
- System flushing: Old systems build up sludge. A professional flush before installation is non-negotiable. Skip this, and your new boiler could fail within a year. Cost: $250-$400.
- Smart thermostat: Not required, but highly recommended. A Wi-Fi-enabled thermostat like the Nest or Hive lets you control heating from your phone. Adds $300-$500, but saves 10-15% on gas annually.
- Radiator upgrades: If your radiators are old or undersized, they won’t work efficiently with a modern boiler. Replacing 3-4 radiators can add $1,000-$1,800.
- Gas pipe upgrades: Older homes sometimes have undersized gas lines. A plumber might need to replace 5-10 meters of pipe to handle the new boiler’s demand. Cost: $600-$1,200.
Ask for a written quote that lists every item. If something’s not listed, assume it’s not included.
When to Repair vs. Replace
Not every broken boiler needs replacing. If your unit is less than 10 years old and the repair is under $800, fixing it often makes sense. Common fixes: a faulty pump ($350), a broken pressure valve ($200), or a cracked heat exchanger ($600-$900).
But if your boiler is over 15 years old, has had multiple repairs in the last two years, or is losing pressure constantly, replacement is cheaper in the long run. Older boilers run at 70-75% efficiency. New condensing boilers hit 90-98%. That’s a 25% drop in gas use. In Adelaide, where winter gas bills average $280/month, switching to a new boiler can save you $70 a month. You’ll recover the cost in 2-3 years.
How to Save Money Without Getting Screwed
You don’t need to pay top dollar for a good boiler. Here’s how to cut costs smartly:
- Get 3 quotes: Don’t pick the cheapest. Pick the one with the clearest breakdown and the most experience in your home type.
- Ask about government rebates: South Australia offers the Home Energy Savings Scheme. You can get up to $1,000 off if you replace an old boiler with a high-efficiency model.
- Book in winter off-season: April to August is slow for boiler installers. You’ll get faster service and sometimes 10% discounts.
- Don’t pay upfront: Only pay 10-20% deposit. The rest should be due after installation and testing.
- Check warranty length: A 7-10 year warranty on parts and labor is standard for quality boilers. Anything less is a red flag.
What Happens After Installation?
Your new boiler comes with a 12-month service requirement to keep the warranty valid. Most installers offer a free annual service as part of the deal. Don’t skip it. A yearly check-up catches small issues before they become $2,000 repairs.
Also, make sure you get the boiler’s manual, warranty card, and a certificate of compliance. This document proves the work was done by a licensed gas fitter. You’ll need it if you ever sell your home.
And if your boiler is making noise again after six months? Call the installer. Reputable companies will come back for free if it’s their work.
Is it cheaper to repair or replace a boiler in Adelaide?
It depends on age and repair cost. If your boiler is under 10 years old and the repair is under $800, fixing it usually makes sense. If it’s over 15 years old, has had multiple repairs, or is inefficient, replacement is almost always cheaper long-term. A new boiler can cut your gas bill by 25%, which pays for itself in 2-3 years.
How long does a new boiler last?
A well-maintained boiler lasts 12-15 years. High-end models like Viessmann or Worcester Bosch can last 18-20 years if serviced annually. Poor installation or skipping maintenance cuts that lifespan in half.
Do I need a new thermostat with my boiler?
Not required, but strongly recommended. A programmable or smart thermostat lets you set heating schedules, turn it off when you’re away, and adjust by room. It can reduce your gas use by 10-15% annually. Most installers bundle them for $300-$500.
Can I install a boiler myself to save money?
No. In South Australia, only licensed gas fitters can legally install gas boilers. DIY installation is illegal, dangerous, and voids your home insurance. Even if you’re handy, the risks far outweigh any savings.
Are there rebates for new boilers in Adelaide?
Yes. The South Australian Home Energy Savings Scheme offers up to $1,000 off for replacing an old boiler with a high-efficiency model (90%+ efficiency). You must use a licensed installer, and the boiler must be on the approved list. Check the SA government website for current qualifying models.
What’s the average monthly gas bill with a new boiler?
In Adelaide, a typical 3-bedroom home with a new high-efficiency boiler spends $180-$220 per month on gas in winter. An older, inefficient boiler could cost $250-$300. The difference comes down to efficiency ratings-new boilers use less gas to produce the same heat.
Final Thoughts
A new boiler isn’t a luxury. It’s a necessity in Adelaide winters. But it’s also one of the biggest home expenses you’ll face. Don’t rush it. Know your options. Compare quotes. Ask questions. And remember: the cheapest boiler isn’t the cheapest in the long run. The one that lasts, works efficiently, and comes with solid support? That’s the real value.
