Deciding whether to repair or replace a Melbourne gas ducted heater involves weighing the cost of the specific fault against the age and condition of the system, the cost of a new installation, and the running cost saving from a more efficient modern unit. This guide provides Melbourne 2025 replacement costs, a practical repair-versus-replace decision framework, and brand and model guidance for Melbourne homeowners at this decision point.
When to Replace Your Melbourne Ducted Heater
The question of replacement is most clearly answered in the following situations:
Cracked heat exchanger
A heat exchanger crack that is producing CO in the house air stream is a replacement-or-cease situation. Heat exchanger replacement as a repair is theoretically possible on some models but the cost typically approaches or exceeds the installed cost of a new heater — making it economically indefensible for any heater over ten years old. If a Melbourne heater is found to have a cracked heat exchanger at an annual service, the honest recommendation is replacement.
Heater over 20 years old with major fault
A heater that has reached or exceeded 20 years and presents with a major fault — blower motor failure, gas valve failure, or ignition PCB failure on a model where parts are limited — warrants a repair-versus-replace calculation. Paying $450 to $750 for a blower motor replacement on a 22-year-old heater has a different value proposition than the same repair on a 10-year-old heater. A technician can provide an honest current-condition assessment.
Multiple repairs in a short period
A heater that has required two or three separate repairs within a 12-month period is likely entering systemic degradation — the cost of each individual repair may be justified, but the pattern indicates the system is at a threshold where multiple further repairs are likely. The cumulative repair investment is better directed toward a replacement.
Star rating and running cost
An old 2-star heater in otherwise working condition still warrants a replacement conversation — not because it is about to fail, but because the running cost saving from a new 6-star unit accumulates quickly. See our running costs guide for the Melbourne cost model. At $360 per year in gas savings, a new 6-star Brivis or Rinnai has a running cost payback contribution that shortens the effective cost of replacement.
Repair vs Replace — The Decision Framework
A practical decision framework for Melbourne homeowners:
| Situation | Recommendation |
|---|---|
| Heater under 10 years old, single fault, repair cost under $400 | Repair — good remaining life ahead |
| Heater 10–15 years old, single fault, repair cost under $500 | Repair — assess heat exchanger condition at service |
| Heater 15–20 years old, repair cost over 30% of replacement | Consider replacement — discuss at service |
| Heater over 20 years old, any major fault | Replace — remaining life does not justify repair cost |
| Any heater — cracked heat exchanger confirmed | Replace — CO safety overrides cost calculation |
| Working 2-star heater, approaching service age | Consider replacement for running cost saving |
Replacement Cost Melbourne 2025
| Scenario | Approximate Cost | Notes |
|---|---|---|
| New gas heater, existing ductwork (small home) | $2,500–$3,200 | Standard townhouse or 3-bedroom home |
| New gas heater, existing ductwork (medium home) | $3,000–$4,500 | 4–5 bedroom Melbourne home, standard installation |
| New gas heater, existing ductwork (large home) | $3,800–$5,500 | Large heater, complex zone system |
| Ductwork replacement required (partial) | Add $500–$1,500 | Some sections requiring replacement |
| Ducted reverse cycle (into existing ductwork) | $4,000–$8,000 | Heating and cooling; higher upfront cost |
These are typical Melbourne 2025 installed prices. Every installation is site-specific — FreshDuct provides a fixed price quote after site inspection. Call 0431 918 137 to arrange a replacement quote.
Which Brands and Models to Consider
For Melbourne residential gas ducted heater replacement, the primary choices are:
Brivis
Brivis remains the most widely recommended brand for Melbourne ducted heating replacement — particularly in homes that already have Brivis installations, as the duct dimensions and zone wiring are often directly compatible with the new Brivis Contour or Evoque models. Brivis’s Lonsdale manufacturing means strong Australian parts availability and technician familiarity across Melbourne. The current Contour and Evoque 6-star range are the premium options; the standard 5-star range is the most cost-effective Melbourne replacement choice.
Rinnai
Rinnai’s current ducted gas heater range is a strong option for Melbourne heater replacement, particularly in homes with existing Rinnai installations where the zone controller wiring is Rinnai-compatible. Rinnai’s current range includes iZone-compatible models, which is an advantage for Melbourne homeowners wanting smart zone scheduling without a premium zone controller built into the heater.
Braemar
Braemar (a brand within the Seeley International group) is made in Albury, NSW, and is a well-regarded option for Melbourne ducted heating replacement. Braemar’s range starts at a competitive price point with solid 5-star and 6-star options. Good parts availability through the Seeley network.
Bonaire
Bonaire offers a competitive Melbourne ducted heating range and is a viable option particularly for price-sensitive replacements where the existing ductwork is in good condition and a straightforward heater swap is all that is required.
What the Replacement Process Involves
A standard Melbourne ducted heater replacement using existing ductwork involves:
- Site inspection and quote: technician assesses heater size required, duct condition, roof space access, existing zone wiring, flue path, and gas supply connection. Fixed price quote provided.
- Old unit removal: gas supply isolated; existing heater disconnected from ductwork, gas, flue, and electrical supply. Old unit removed from roof space and disposed.
- New unit installation: new heater positioned and secured in roof space; connected to existing ductwork; gas supply reconnected and gas pressure tested; flue connected and checked; electrical supply connected.
- Controller installation: new wall controller fitted if required (most modern replacements include a new controller); low-voltage zone wiring connected; zone configuration programmed.
- Commissioning: heater started; combustion performance tested; all zones commanded and verified; thermostat calibration confirmed; householder briefed on operation.
A straightforward Melbourne heater replacement in a clear roof space with existing ductwork in good condition typically takes 3 to 5 hours. Systems with complex zone rewiring, ductwork modifications, or difficult roof space access take longer.