Replacing a Brivis, Bonaire or Braemar Gas Heater With Reverse Cycle Ducted Air Conditioning in Melbourne

The Changeover Process, Your VEU Rebate Options and Why New Ductwork Is Part of the Job

TL;DR: You can replace an ageing Brivis, Bonaire or Braemar gas ducted heater with reverse cycle ducted air conditioning that heats and cools your whole home. The changeover involves a new indoor unit, outdoor unit and new insulated ductwork, as existing gas ducts are not suited to refrigerated air. Eligible upgrades can attract a Victorian Energy Upgrades (VEU) discount when it is arranged before installation.

Why Are Melbourne Homeowners Replacing Gas Ducted Heating?

Melbourne homeowners are replacing gas ducted heating because their systems are ageing, gas costs are a growing concern, and reverse cycle systems deliver heating and cooling from one unit. Victoria’s energy policy is also moving homes away from gas.

The most common reasons we hear during a gas heater replacement in Melbourne include:

• Ageing systems: Many Brivis, Bonaire and Braemar heaters were installed 15 to 25 years ago. Older units become less reliable, harder to source parts for and less efficient.
• Gas prices in Victoria: Households are paying closer attention to running costs as gas prices change and daily supply charges add up.
• Year-round comfort: A gas ducted heater only heats. Reverse cycle ducted air conditioning in Melbourne homes covers cold winters and hot summers with one system.
• Energy policy shift: Under Victoria’s Gas Substitution Roadmap, new homes that need a planning permit can no longer connect to gas, and government programs now favour electric heating.
• 2027 rental regulations: From 1 March 2027, when a heater in a Victorian rental property fails and cannot be repaired, it must be replaced with energy-efficient electric heating. Our guide to Victoria’s 2027 rental heating standards explains what landlords need to know.

For a side-by-side comparison of the two technologies, read our guide to gas ducted heating vs reverse cycle.

Can You Reuse Your Existing Gas Heating Ducts?

In almost every Melbourne home, existing gas heating ducts are not suitable for a reverse cycle system. When you replace gas ducted heating with reverse cycle, King & Sons installs new insulated ductwork throughout.

This is the most common misconception we encounter. The ducts look similar, so it seems logical to keep them. The reasons they need replacing are practical:

• Insulation and condensation: Gas heating ducts were designed to carry warm air only. Many older ducts have low insulation ratings, and some older homes have uninsulated sheet metal sections. When a reverse cycle system pushes cold air through these ducts in summer, moisture condenses on the outside, which can drip onto ceilings and cause water damage and mould.
• Floor vents versus ceiling vents: Many gas ducted systems deliver heat through floor vents. Cool air sinks, so floor outlets perform poorly in cooling mode. Refrigerated systems are designed around ceiling vents.
• Different plenum and damper layouts: The plenum, the box that connects the indoor unit to the duct runs, is sized differently for a refrigerated system. Zone dampers and motorised dampers from an old gas system rarely match the new unit’s airflow requirements.
• Airflow and sizing: Reverse cycle systems move a different volume of air at different pressures. Duct sizes designed for a gas furnace can restrict airflow, reduce efficiency and increase noise.
• Age and condition: Ducts that have spent decades in a hot roof cavity often have split joins, crushed sections and degraded insulation.

Reusing old gas ducts may look cheaper on paper, but it risks condensation damage, poor cooling and a system that never performs to its rating. Full duct replacement is the reliable path.

What Does the Changeover Process Involve?

The changeover from gas ducted heating to reverse cycle ducted air conditioning follows a clear sequence, from site inspection to commissioning. Most homes are completed within a few days once installation begins.

1. Free site inspection: A licensed technician inspects your home, your current Brivis, Bonaire or Braemar heater, the roof cavity, ceiling layout and switchboard.
2. System sizing: We calculate the heating and cooling load for your home, considering floor area, ceiling height, insulation, window orientation and how you use each room.
3. Fixed upfront quote: You receive a fixed price quote that includes the system, ductwork, electrical work and any VEU discount you are eligible for.
4. Gas heater decommissioning: We disconnect and remove the old gas heater. A licensed gasfitter caps the gas supply to the appliance.
5. Duct removal and replacement: Old ductwork is removed from the roof cavity, and new insulated ductwork, plenum and zone dampers are installed.
6. Indoor and outdoor unit installation: The indoor unit goes in the roof cavity, and the outdoor unit is mounted on a suitable outside wall or slab.
7. Refrigerant piping and electrical work: Our ARCtick-certified technicians run refrigerant piping between the units, and a licensed electrician connects the system to your switchboard.
8. Ceiling vents and return air grille: New ceiling vents are cut in, and a correctly sized return air grille is fitted.
9. Commissioning: We test the system in heating and cooling modes, check airflow to every vent, set up your zone controller and show you how to use it.

To understand the broader investment, see our guide to ducted air conditioning cost in Melbourne.

Which Reverse Cycle Systems Replace Gas Ducted Heaters?

Inverter reverse cycle ducted systems from Daikin, Mitsubishi Electric and Panasonic are popular replacements for gas ducted heaters in Melbourne. All three use heat pump technology that performs well in Melbourne’s climate.

A heat pump does not burn fuel to make heat. It moves heat from the outside air into your home, even on cold days. Its efficiency is measured by its coefficient of performance (COP ratio), which compares the heat delivered with the electricity used. A COP of 3, for example, means the system delivers three units of heat for every unit of electricity it consumes.

In climate zone 6, where Melbourne winters are cold but rarely extreme, modern inverter heat pumps maintain strong heating output through typical winter conditions. Inverter technology also adjusts compressor speed to match demand, avoiding the energy waste of constant stop-start cycling.

When comparing models, look at:

• Rated heating capacity (kW): This must match the calculated heating load of your home.
• Energy efficiency and star rating: Higher-rated systems cost less to run over their lifespan.
• Zoning and controls: Zone control lets you heat only the rooms you are using.
• VEU approval: Only approved models qualify for the VEU discount.

Explore the systems we install on our ducted air conditioning and heating.

Can You Get a VEU Rebate for Gas Heater Replacement?

Yes, most Melbourne households replacing a ducted gas heater with an approved high-efficiency reverse cycle ducted system can access a Victorian Energy Upgrades discount. The discount must be arranged before installation begins.

The VEU program offers point-of-sale discounts on eligible energy efficiency upgrades. Key eligibility points include:

• the new system must be a VEU-approved, high-efficiency reverse cycle air conditioner that heats and cools
• home installations must come with a minimum five-year warranty
• the gas heater being replaced must be more than two years old
• the old heater must be decommissioned as part of the upgrade
• The discount must be applied by, or through, an accredited provider before work starts.

The Victorian Government’s heating and cooling discounts page lists current indicative discounts for replacing a ducted gas heater with a ducted reverse cycle system. The final amount depends on the system size and the current certificate price, so King & Sons includes it in your fixed upfront quote. Our dedicated guide to the VEU rebate for reverse cycle ducted air conditioning covers the process in detail.

How Do Running Costs Compare: Gas Ducted Heating vs Reverse Cycle?

For most Melbourne homes, an efficient reverse cycle ducted system costs less to run for heating than an older gas ducted heater. The gap is widest when the gas heater is old and low-rated.

The difference comes from efficiency. A gas heater converts gas into heat at less than 100 per cent efficiency, and older units lose more heat through the flue. A heat pump moves heat rather than generating it, so it can deliver several units of heat for each unit of electricity.

Your actual running costs depend on:

• your gas and electricity tariffs, including daily supply charges
• the age and star rating of your current heater
• the efficiency of the new system
• your home’s insulation and draught sealing
• how many zones you heat and for how long
• whether you have rooftop solar to offset daytime use.

If you switch fully to electric heating, cooking and hot water, you may also be able to remove your gas connection and its daily supply charge. We do not quote generic savings figures because every home is different. For more context on costs, see our guide on how much ducted heating costs in Melbourne, and request a fixed upfront quote for your home.

What Happens to Old Refrigerant Systems and R22?

Gas ducted heaters do not contain refrigerant, but many Melbourne homes also have an older split system or add-on cooler that does. If that equipment is removed during your changeover, the refrigerant must be recovered by a licensed technician.

R22 is an older refrigerant found in many air conditioners installed before the 2010s. It damages the ozone layer and must never be vented to the atmosphere. Only technicians holding a refrigerant handling licence issued through the Australian Refrigeration Council (ARCtick) can legally recover and dispose of it.

King & Sons is ARCtick certified and VBA registered. When we decommission any refrigerated equipment as part of a gas heater replacement, we recover the refrigerant safely and dispose of the old unit responsibly.

Frequently Asked Questions

Ready to Replace Your Gas Heater With Reverse Cycle Ducted Air Conditioning?

If your Brivis, Bonaire or Braemar gas heater is showing its age, King & Sons can plan your changeover from start to finish. Our licensed technicians handle the inspection, sizing, ductwork, installation and VEU paperwork, and you receive a fixed upfront quote before any work begins. Contact King & Sons to book your free site inspection.