How Much Does Ducted Heating Replacement Cost? [2025]
There are so many gas ducted heating options available in Melbourne that it’s hard to find accurate, up-to-date costs.
In this 2025 price guide, we analyse all the important factors to give you a solid understanding of how much ducted heating replacement costs.
If you’ve had your gas heater for over 10–15 years, your system is deteriorating, or it’s undergoing regular repairs, it’s time to start looking at replacements.
Having conducted thousands of replacements over the past few decades, we can provide an accurate cost breakdown to help you budget for your upcoming ducted heating replacement.
If you’ve been wondering how much it costs to replace ducted heating, you’ll find out here.
*All prices are estimates.
Key Takeaways
- Ducted heating replacement typically costs $1,900 – $6,000, depending on brand, home size, star rating, and system complexity.
- Ductwork and controllers are often reusable, reducing costs.
- Brivis is a premium option; Braemar and Bonaire are mid-range; Kaden is budget-friendly.
Contents
Gas Ducted Heating Replacement Cost
Ducted heating replacement can cost between $1,900 – $6,000, with brand choice, complexity of replacement, star rating, and size and efficiency of the unit being the biggest price movers.
To give you a better idea, we’ll use a popular option in Melbourne, the Brivis StarPro 4.
For a small home, 15kW is a common capacity, and this costs anywhere from $2,000-$3,000.
For a medium sized home, 21 kW will provide quality heating, and this replacement can cost $3,000-$4,000.
For larger homes with many rooms, 30-35kW will be necessary, costing roughly $5,000-$6,000.
This is also considering that a lot of duct work can be reused, which saves you some money.
Oftentimes the controller can also be reused.
Ducted heating unit replacement price table
| Home Size | Brivis Model | Capacity (kW) | Estimated Replacement Cost (AUD) |
|---|---|---|---|
| Small | SP415UN | 15 | $1,900 – $3,000 |
| Medium | SP421UN | 21 | $3,000 – $4,000 |
| Large | SP430UN | 30 | $5,000 – $6,000 |
Factors that influence the cost to replace ducted heating
Size of the home
The bigger the home, the more heating capacity your gas ducted heater needs.
For a rough idea of what size you need, refer to the table above.
An oversized unit can overshoot the amount of heating capacity needed to heat your home, resulting in unwanted consequences such as higher energy bills.
If you have an undersized unit, your system can overwork as it can’t reach the adequate temperature, causing premature issues and repairs.
If you live in a small home or apartment, aim for a unit with no less than 15kw and no more than 20kW.
These homes are somewhere between 50-150 square metres.
If you live in a medium or average sized home in Melbourne, you’ll need a unit that is around 20-25kW.
We class a medium sized home anywhere between 150-250 square metres.
For a large home, you’ll need 30-35kW to power your whole place effectively.
Larger homes are 250 square metres or more.
Brand of unit
Brands are very important when choosing the right gas ducted heater. It’s important to know how your brand choice can impact the overall replacement cost.
Brivis is by far the most premium option and customers swear by them.
Their superior build quality means better longevity, and they’ll often be on the upper end of the range around $4,000.
Bonaire and Braemar are similarly priced as a mid market option, offering quality performance and a replacement for around $3,500.
The last option is Kaden, if you’re on a bit more of a budget this brand costs around $3,000 and punches above its weight.
Zoning/ductwork changes
Ductwork and zoning is often very easy to reuse as it’s already set up across your home, therefore not requiring full installation.
Ductwork is oftentimes a costly part of installation, so just connecting the existing ductwork to the replacement system is very easy.
There are rare cases where the ductwork is of poor quality or degraded, in these cases we will suggest replacement or repair of those parts.
If you’ve had structural changes to your home it might also need repairing or further assessment.
Energy-efficiency ratings
The energy efficiency rating for gas appliances is different from the zoned energy rating label.
For Gas appliances it goes from 1-6, 6 star rating being the most efficient gas heaters.
Most gas heaters don’t go below 3 stars.
At 3 stars, you won’t get the best energy efficiency but you’ll get great value for money.
For instance, the Brivis Buffalo BX3C is an extremely popular 3-star choice.
A 6-star option built for pure energy-efficiency would be the Brivis StarPro 6
The cost of replacing these two units can be a difference of around $1,000-$1,500 depending on where your heating installer gets their gas heaters from.
Complexity of removal/installation
Gas ducted heating replacement is actually not a complex process.
When a licenced HVAC technician inspects your existing system, they will make you aware of any complexities or issues affecting the replacement.
Choosing to add cooling to your ducted heating will make the process more lengthy, complex and costly.
Replacement vs Repair – Which is Better?
To evaluate whether your existing ducted heating needs to be repaired or replaced you need to consider the following factors:
- Efficiency
- Cost/Severity/Frequency of repairs
- Age
- Service history
A gas heater should last at least 15 years, so if your system isn’t nearing this age you shouldn’t be considering a replacement.
It’s not unusual for a gas heater to last 20 years with the proper care.
However if you have not been actively maintaining your system this will certainly take a few years off its lifespan.
When your system is constantly breaking down or has had a few repairs in a short period, this can indicate that the system is failing meaning a replacement could be necessary to save costs, especially if those repairs are major components.
The best way to know whether you need a repair or replacement is to contact ducted heating specialists to inspect your system.
Is your existing gas heater having issues? Contact or ducted heating repairs team.
Replacement Time & Process
As mentioned earlier, ducted heating replacement is a relatively straightforward process.
Firstly, a HVAC technician will come out to assess your home’s existing system.
They’ll suggest what needs to be done in terms of replacements and suggest a few options depending on your budget.
This will also include determining whether the ductwork, controller, and other parts of the system can be reused.
Once all the information is gathered, we’ll present a quote and you’ll agree to start.
On the designated day, the HVAC team will replace the unit and ensure the system is functioning smoothly.
Majority of the time this is completed on the same day.
Need a gas ducted heating replacement? Call our experts!
Thomas Air Conditioning offers value-for-money ducted heating replacement prices that are all backed by a 5-year workmanship guarantee.
Our team will evaluate your system and recommend the best option moving forward.
If it’s more beneficial for your system to be repaired, we’ll inform you, so you can save money.
We also recommend routine maintenance, which will extend the life of your system.
Contact our team for a reliable assessment and free quote for your ducted heating system.
FAQ
How long does ducted heating last?
It’s very common for gas heaters to last 20 years, as they are extremely durable systems.
Is ducted gas heating being phased out?
For new homes with planning permits, gas connections are banned as of 1st January 2024. This doesn’t mean you can’t replace your existing gas ducted system with another.
Are there rebates for replacing gas heating?
There are rebates for replacing gas ducted heating with more efficient air conditioners. You won’t get a rebate for replacing a gas heater with another gas heater.