Is It Better to Repair or Replace a Boiler? A Practical Guide for Perth Homeowners

When your boiler starts making strange noises, leaking water, or just won’t heat your home anymore, you’re faced with a tough call: fix it or swap it out. It’s not just about money-it’s about safety, comfort, and long-term value. In Perth, where winters can turn chilly and gas prices keep climbing, this decision can make a real difference to your monthly bills and peace of mind.

How old is your boiler?

The age of your boiler is the first thing that should guide your decision. Most gas boilers last between 10 and 15 years. If yours is older than 12, even a small repair might not be worth it. Why? Because parts become harder to find, efficiency drops, and breakdowns get more frequent. A 15-year-old boiler might only run at 70% efficiency, while a new A-rated model hits 94% or higher. That’s a 24% jump in efficiency-meaning you’re burning more gas just to get the same heat.

I’ve seen homeowners spend $800 fixing a 14-year-old boiler, only to have it fail again six months later. That’s $800 down the drain, literally. A new boiler costs more upfront, but it pays for itself in lower gas bills over time. In Perth, where gas bills can hit $200 a month in winter, even a 15% reduction saves you $30 a month. That’s $360 a year. In under three years, you’ve covered the cost of a new unit.

What’s the cost of repair vs. replacement?

Let’s break it down. A typical boiler repair in Perth runs between $300 and $800, depending on the issue. Common fixes include replacing the pump, thermostat, or pressure valve. But here’s the catch: if your boiler is over 10 years old, that repair is often just a temporary band-aid. You’re not fixing the system-you’re delaying the inevitable.

A new boiler, on the other hand, costs between $3,500 and $6,500 installed, including removal of the old unit and disposal. That sounds steep, but it’s not just a one-time cost. New boilers come with 5- to 10-year warranties. They’re quieter, safer, and smarter. Many now connect to apps so you can adjust the temperature from your phone. Some even learn your routine and adjust heating automatically.

Here’s a simple rule: if the repair costs more than 50% of what a new boiler would cost, walk away. That’s not a suggestion-it’s a standard industry guideline for a reason. Spending $3,000 to fix a $5,000 boiler? That’s not a repair. That’s a gamble.

Is your boiler still under warranty?

If your boiler is still under warranty, repair is the obvious choice. Most manufacturers offer 2 to 5 years of coverage on parts and labor. Some even cover the heat exchanger, the most expensive part. Check your paperwork. If you bought it new in 2023 and it broke in 2025, you’re likely covered. Call the installer or manufacturer. They’ll send someone out at no cost to you.

But if the warranty expired last year? Don’t assume you’re safe. Many extended warranties are sold as add-ons and are easy to miss. Dig out your receipt or log into the installer’s portal. If you can’t find it, call the company. They often keep digital records. If you’re not covered, then it’s time to weigh repair against replacement again-with cold, hard numbers.

Are you planning to stay in your home?

This one’s easy to overlook. If you’re planning to sell your home in the next two years, a new boiler can be a huge selling point. Buyers in Perth are increasingly asking for energy-efficient heating. A boiler that’s less than five years old with a warranty can add 2% to 5% to your home’s value. That’s $10,000 to $25,000 extra on a $500,000 house.

On the flip side, if you’re renting out the property, you might think a cheap repair makes sense. But tenants notice when the heating takes 45 minutes to warm up. They complain. They leave. And vacancy costs more than a new boiler. A reliable, efficient system keeps tenants happy and reduces turnover.

What about safety?

Old boilers aren’t just inefficient-they can be dangerous. Carbon monoxide leaks are silent killers. A cracked heat exchanger, a failing gas valve, or a blocked flue can release deadly gas into your home. In 2024, WA Health recorded 17 cases of carbon monoxide poisoning linked to aging gas appliances. That’s not a statistic-it’s someone’s family.

New boilers come with multiple safety sensors. They shut off automatically if they detect a leak, low water pressure, or overheating. They’re tested to AS/NZS 5601.1 standards. Older models? They might not even have a flame failure device. That’s a basic safety feature that’s been required since 2005. If your boiler predates that, it’s not just outdated-it’s risky.

What are your energy bills doing?

Check your last three gas bills. If they’ve jumped more than 15% over the past year-and you haven’t changed your usage-it’s a red flag. Your boiler is working harder. That means it’s inefficient. Even if it still heats your home, it’s burning more gas to do it.

Compare your usage to the average. A typical Perth household with a 24kW boiler uses about 12,000 kWh per year. If yours is using 15,000 kWh or more, you’re paying $500 to $800 extra annually just to stay warm. That’s money you could be saving with a modern condensing boiler.

Is your boiler the right size for your home?

Size matters. A boiler that’s too small won’t heat your home properly. One that’s too big cycles on and off too often, wasting energy and wearing out faster. Many older homes in Perth still have boilers sized for 1980s insulation levels. Today’s homes are better sealed. You might not need a 30kW unit anymore. A 24kW or even 20kW model could be perfect.

A qualified technician can do a heat loss calculation. It’s free with most quotes. If your current boiler is oversized, replacing it with the right-sized unit can save you 10% to 15% on energy use alone. That’s not just efficiency-it’s precision.

What’s the environmental impact?

Boilers are a major source of household emissions. In Western Australia, residential gas heating accounts for nearly 12% of household carbon output. A new boiler cuts that significantly. A 94% efficient model emits about 1.2 tonnes less CO2 per year than a 75% efficient one. That’s like taking a car off the road for three months.

Perth City Council is pushing for greener homes. Future regulations may require minimum efficiency ratings for rental properties. If you’re a landlord, replacing now protects you from future compliance costs.

When to choose repair

There are times when repair makes sense:

• Your boiler is under 8 years old and still under warranty
• The issue is a simple fix: thermostat, pump, or pressure sensor
• You’re on a tight budget and plan to move soon
• The boiler has been well-maintained with annual services

Even then, get a second opinion. Some technicians push repairs to keep jobs coming. Ask: "If this were your house, would you fix it or replace it?"

When to choose replacement

Replace your boiler if:

• It’s over 12 years old
• Repair costs more than half the price of a new unit
• You’ve had two or more repairs in the last year
• Your energy bills have risen sharply
• You smell gas, hear banging, or see water leaks
• You’re planning to sell or upgrade your home

Don’t wait for it to die in the middle of winter. That’s when prices spike and technicians are booked for weeks.

What to look for in a new boiler

When you’re ready to replace, focus on three things:

1. Efficiency rating-Look for an A-rated condensing boiler. Anything below B is outdated.
2. Size-Match it to your home’s heat loss, not the old unit’s size. A 20kW to 24kW unit suits most Perth homes.
3. Warranty-Choose at least a 7-year parts and labor warranty. Brands like Worcester Bosch, Vaillant, and Baxi offer this.

Ask about government rebates. Western Australia’s Energy Efficiency Program offers up to $1,000 for replacing old gas boilers with high-efficiency models. You can combine this with installer discounts.

Final decision checklist

Before you decide, run through this quick checklist:

• Is the boiler older than 12 years? → Replace
• Has it cost over $800 in repairs in the last year? → Replace
• Are your gas bills more than 15% higher than last year? → Replace
• Do you feel cold spots in your home? → Replace
• Is the boiler making loud banging or gurgling noises? → Replace
• Is it under warranty and under 8 years old? → Repair
• Is the repair under $500 and the boiler under 10 years? → Repair

If you checked more than three "Replace" boxes, it’s time to call a licensed gas fitter. Don’t delay. Winter is coming.