Published by Speedy Services Today | Sunbury, Victoria | Updated 2026
Ducted gas heating is one of the most significant home improvements a Sunbury household can make – and one of the most confusing to price. Ask three companies for a quote and you might get three numbers ranging from $4,000 to over $12,000. The spread is not random. It reflects genuinely different products, installation scopes, and sometimes, very different levels of honesty.
This guide breaks down exactly what drives ducted heating installation costs in Sunbury in 2026, what a fair quote looks like, and what to watch for when comparing proposals.
What Does a Ducted Gas Heating System Actually Cost to Install?
For a standard residential property in Sunbury, the total cost to supply and install a new ducted gas heating system typically falls in the following ranges:
| Home Size | Typical Installation Cost | Notes |
| 2-3 bedroom unit or townhouse | $3,500 – $5,500 | Smaller duct run, fewer outlets |
| 3-4 bedroom single storey | $5,000 – $7,500 | Most common Sunbury scenario |
| 4-5 bedroom single storey | $6,500 – $9,500 | Larger system, more duct |
| Double storey home | $8,000 – $13,000+ | Additional complexity and materials |
| Replacement (existing ducts intact) | $2,500 – $4,500 | Unit replacement only, reusing ductwork |
These are supply-and-install prices. They should include the unit, all ductwork, ceiling outlets (outlets/grilles), a thermostat, and the gas connection work. If a quote is significantly below these ranges, ask what it excludes before signing anything.
The 6 Factors That Move the Price Up or Down
1. The Unit Itself
Gas ducted heaters are rated by star efficiency and output capacity (kilowatts). A 5-star 14kW unit costs more than a 2-star 14kW unit, but uses substantially less gas over its lifetime. For Sunbury’s climate – where winters are genuinely cold – the efficiency premium is usually recovered within a few years of operation.
Brands vary in quality, availability of parts, and warranty terms. A ducted heating Sunbury specialist who works with multiple brands can give you an honest comparison rather than steering you toward whatever earns the best margin.
2. Ductwork – New vs. Reusing Existing
If your home has existing ductwork in reasonable condition, replacing only the heating unit reduces cost significantly. A unit swap-out on existing ducts is the most cost-effective scenario.
If ductwork needs to be laid fresh, materials and labour for the duct run add $1,500 to $4,000+ depending on home size and accessibility. Double storey homes require more complex routing, which pushes cost higher.
3. Number of Outlets (Zones)
Each ceiling outlet adds to the duct run and to the materials cost. A 10-outlet system costs more than a 6-outlet system of the same unit size. Zoning controls – which let you heat only occupied rooms rather than the whole house – add upfront cost but reduce operating costs meaningfully over time.
4. Gas Connection Work
If your home already has a gas supply and the metre is accessible, connecting a new heater is straightforward. If you are adding gas to a property for the first time, or if the existing gas line needs upgrading to handle the heater’s demand, gas connection costs add $500 to $2,000+ to the project. This work must be done by a licensed gas fitter – in Victoria, that is also a licensed plumber in most cases.
5. Roof Space Access and Insulation
Most residential ducting in Sunbury runs through roof space. A roof space that is well-insulated, easy to access, and not crammed with wiring or structural obstructions is faster and cheaper to work in. Difficult access increases labour hours and therefore total cost.
6. Thermostat and Control Options
A standard single-zone wall thermostat is included in most base quotes. Upgraded controls – including Wi-Fi enabled smart thermostats or multi-zone controllers – add $200 to $800 depending on the system.
Seasonal specials: Speedy Services Today currently offers $200 off ducted heater replacements for eligible Sunbury customers. It is worth asking about current offers before getting a quote locked in.
Replacement vs. New Installation: Which Makes More Sense?
If your existing ducted heater is under 10 years old and the fault is a component (burner, igniter, thermostat, board), repair is almost always worth it. A repair from a qualified Sunbury plumber and gas fitter typically costs $250 to $700 for most common faults.
If the unit is over 12 to 15 years old, a replacement is usually the smarter financial decision even if the current fault is repairable. Older units are less efficient, parts become harder to source, and another fault is statistically likely within a few years.
The efficiency argument is real: a modern 5-star gas ducted system uses roughly 25 to 35 percent less gas than a comparable unit from 15 years ago. Over a Sunbury winter, that difference shows up in the energy bill.
What Annual Servicing Should Cost – and Why It Matters
An annual ducted heating service typically costs $150 to $300 in Sunbury. It includes checking the burner, cleaning filters, testing the thermostat, inspecting the heat exchanger, and testing for carbon monoxide. That last one is not optional – a cracked heat exchanger is a serious safety issue.
Skipping annual servicing is one of the more common false economies in home maintenance. A heater that breaks down in the first week of June costs you an emergency call-out rate, faster deterioration of components, and potentially a bill for parts that would have been caught and cleaned during a standard service.
Getting a Quote That Covers Everything
A thorough ducted heating quote should itemise:
- The make, model, and star rating of the unit
- Number of outlets and their locations
- Whether ductwork is new or reused (and condition notes if reused)
- Gas connection scope – what is and is not included
- Thermostat type and zone controls
- Warranty terms on both the unit and the installation workmanship
- Any exclusions – access difficulties, electrical upgrades, patching after installation
A quote that is just a single line – “supply and install ducted heating – $X,XXX” – leaves too much room for surprises. Get the detail before you commit.
Why Local Matters for Ducted Heating in Sunbury
A locally based gas plumber who services your area regularly knows Sunbury’s housing stock – the roof space access challenges in older properties, the gas infrastructure typical in the area, and the weather patterns that determine the right system size. That local knowledge affects both the quality of the recommendation and the speed of any future service call.
It also means someone is actually accountable if something is not right. A company based 60km away with no ongoing presence in Sunbury is harder to get back on site for a warranty issue than one based locally with a reputation to protect.
Speedy Services Today is a family-owned plumbing, heating and cooling business based in Sunbury. They are fully licensed for gas fitting and ducted heating installation, and offer upfront pricing with a lifetime workmanship warranty. For ducted heating quotes in Sunbury and surrounding suburbs, call +61 451 645 672 or visit speedyservicestoday.com.au.
