What a promise to reuse the ducts should mean
A gas heater replacement and a conversion to ducted reverse cycle are different projects. Keeping the visible grilles may be straightforward while retaining every hidden branch is unsuitable. Conversely, removing an entire network without inspecting it can discard useful components. Ask the installer to name the items being reused: outlets, outlet boots, branch ducts, main supply, return duct, return grille and zone dampers. The word ductwork alone does not tell you which of those items the price includes.
For a Ballarat homeowner changing a familiar gas system, the useful question is whether the retained parts meet the requirements of the proposed model and the rooms it will serve. A quote based only on the old heater's label does not answer that question. Before comparing offers, request a drawing showing the proposed indoor unit, main connections and retained branches. Mark any rooms added since the original installation. A back room enclosed after the ducts were installed may never have been included in the original design.
Establish what is actually under the floor or above the ceiling
Start with records you already have: equipment model, installation paperwork, any duct repairs and photographs taken during previous building work. Do not enter a difficult roof or subfloor space just to prepare an enquiry. An inspection should identify accessible and inaccessible areas, with photographs tied to room names. A general photograph of a shiny duct near the access hatch cannot establish the condition of the network at the far end of the house.
Ask for the findings to distinguish damage from suitability. A disconnected branch is a repair issue; a sound branch that does not suit the new design is a different reason for replacement. Torn insulation, crushed sections and poorly supported runs deserve separate descriptions. If a contractor cannot inspect a concealed section, have that recorded as an uncertainty with a method for resolving it. This is particularly useful in an established Wendouree or Sebastopol house where later renovations may hide the original duct route. The suburb alone does not establish the condition or construction.
Assess cooling as well as heating
A network that has distributed warm air must be assessed for its proposed cooling use. Do not accept a blanket statement that all heating ducts work for cooling, or that none can. Ask the designer to document the required airflow and the suitability of the duct sizes, insulation and connections for the selected equipment. The Australian Government's Your Home heating and cooling guidance explains the importance of insulated ducts and well-designed ducted systems. It is background guidance, not approval of your existing installation.
The quote should explain how the cooling assessment changes the retained scope. If extra insulation, a different return arrangement or replacement branches are required, those items should be visible before the equipment is ordered. Ask how the installer will check for condensation risk around retained cold-air components. A homeowner does not need to calculate this from a photograph. The important purchasing decision is to require the assessment and allocate responsibility for any resulting work, rather than discovering after commissioning that only the indoor and outdoor machines were included.
Keep the grille decision separate from the duct decision
The existing floor or ceiling grille may be a good visual fit for the room but a poor match to the proposed air distribution. Ask whether the grille will remain for appearance, whether the boot behind it is retained, and whether the connecting branch changes. These are separate choices. If an old outlet is abandoned, specify who closes the opening, makes good the floor or ceiling, and matches the finish. A heating contractor's installation price should not be assumed to include decorative repairs.
In a Ballarat East home with timber floors or detailed ceilings, the consequence of moving an outlet can matter as much as the equipment choice. Photograph the finish and mark which openings you would prefer to retain. Then ask the designer to explain any performance compromise. Keeping an opening because it is convenient should be a deliberate decision, not an undocumented assumption. Conversely, a proposed new ceiling outlet should be shown against lights, joinery and furniture before anyone cuts an opening.
Recheck the return route and the rooms you actually use
Changing the supply equipment without reviewing the return path leaves a large part of the design unanswered. Ask where air from each occupied room is intended to return and whether the return duct and grille are included in the inspection. If you normally shut bedroom doors at night, tell the designer that explicitly. A system demonstrated with every door open has not demonstrated the way that household uses it. The return arrangement must be assessed as part of the conversion rather than treated as an optional accessory.
Write down the combinations that matter: living areas while bedrooms are empty, bedrooms during the evening, or a study used while the rest of the home is quiet. These are design cases, not instructions to close arbitrary outlets yourself. The existing Ballarat zoning guide explains the broader choice. For reuse approval, request confirmation that the retained ducts and dampers work with the proposed operating combinations and the selected equipment's requirements. A new touchscreen cannot establish that by itself.
Compare full reuse, selective replacement and a new network
Full reuse is an option to investigate when the system can be properly inspected and the designer accepts its suitability. It should come with a defined retained scope and commissioning checks. Selective replacement may be preferable when some branches are suitable and others need a new route or size. A completely new network may be justified when the layout changes substantially or too much of the old network cannot be accepted. None of these outcomes can responsibly be selected from the house's age alone.
Compare the alternatives using the same rooms, comfort brief and equipment requirements. An offer for complete replacement may also include new return air, controls and making good, while a cheaper reuse offer may exclude them. Ask each installer to explain what remains unresolved and how variations will be approved. The decision should not depend on a generic percentage saving. A clear retained-versus-new schedule is more useful than an unsupported claim that reuse always pays or that replacement always improves comfort.
Coordinate removal and access before the conversion day
List what happens to the old heater, its connections and any redundant penetrations. Ask who carries out each part and who leaves the property weatherproof and tidy. Removing the old plant may expose an opening that needs a separate building trade. If the new indoor unit occupies a different space, ask how it will be brought in and later serviced. An apparently convenient reuse plan can become disruptive when the access route has not been checked.
For occupied homes, agree which areas need to be clear and how the household will manage the changeover. Do not infer a guaranteed installation duration from another house's job. Request a sequence that identifies inspection, any opening-up work, approval of concealed changes, equipment installation and testing. If unknown duct sections are discovered only after work begins, you should know whether the installer will pause for approval, offer an alternative route or leave a temporary safe condition while the revised scope is agreed.
Require evidence at handover
The handover should make the reuse decision understandable to a future service technician. Keep the final equipment details, the duct layout as installed, photographs of repaired sections and a list of retained components. Ask the installer to demonstrate the agreed operating combinations and explain what was checked during commissioning. Record any room that could not be tested as intended and how it will be revisited. A signed invoice alone does not explain whether the original reuse assumptions proved correct.
Warranty responsibilities should also be explicit. Ask which new items are covered by the installation and product arrangements, what applies to retained components and who to contact if a problem appears at an old-to-new connection. Avoid treating a broad statement about the new machine as a promise about every existing duct. If another contractor later changes insulation or builds an extension, keep those records with the conversion paperwork so the next person can understand what changed after the original acceptance.
Read the quote as a set of boundaries
A useful quote answers practical edge cases. If one concealed branch is damaged, is opening the ceiling included? If an outlet must move, who repairs the old hole? If the return grille changes size, does the price include the wall or ceiling finish? If a retained damper is incompatible, has replacement been allowed for? These questions are specific enough to obtain written answers and prevent two apparently similar quotes from describing quite different jobs.
Ask for exclusions in ordinary language. A phrase such as existing ductwork by others may shift an important responsibility without explaining it to the homeowner. Request that the installer identify what they are accepting, what they are merely connecting to, and what they have not inspected. If the answer remains unclear, do not resolve it by assuming the most generous interpretation. Have the scope corrected before authorising the work, while alternative layouts and equipment selections are still practical.
When a different approach deserves consideration
If retaining ducts requires awkward routes, major disturbance or compromises in the rooms you use most, ask for a comparison with a redesigned ducted layout or a separate room system. This does not mean abandoning ducted heating because one branch needs attention. It means comparing the actual construction work and operating brief rather than protecting an existing network at any cost. The gas versus reverse-cycle guide provides the wider technology comparison.
Where roof access is the limiting issue, use the low roof-space guide before agreeing to new ceiling routes. Where an extension changes the floor plan, read the extension integration guide. Prepare the existing model, a rough room plan and your preferred occupied-room combinations for the enquiry. Those details help frame an inspection without pretending that an online checklist can approve a hidden installation.