Duct cleaning is an unregulated trade in Victoria. There is no licence required, no mandated equipment standard, and no minimum qualification. This means the quality range is enormous — from professional operators using industrial-grade negative pressure equipment and trained technicians to cash-in-hand operators using a domestic vacuum and a brush. Choosing the wrong company is not just a waste of money; it can result in damaged ductwork that costs significantly more to fix than the cleaning itself.
This guide provides the specific questions to ask and the warning signs to avoid when evaluating Melbourne duct cleaning companies.
Questions to Ask Before Booking a Melbourne Duct Cleaner
1. Do you use a negative pressure extraction machine?
This is the single most important question. As covered in our guide on duct cleaning equipment, negative pressure extraction is what makes professional cleaning effective — it captures dislodged debris rather than redistributing it. A company that cleans by vacuuming at register openings only (no negative pressure machine connected to the system) is not delivering a thorough clean regardless of how long they spend at the property.
A professional company will answer this question immediately and confidently. They will describe the machine as a negative pressure unit or extraction unit connected to the duct system at the return air or trunk line. If the company is evasive or pivots to talking about their “high-powered vacuum” without mentioning system-wide negative pressure, this is a warning sign.
2. What does the quoted price cover — and what costs extra?
The base price for a duct clean does not always include everything. Optional extras such as filter replacement and sanitisation fogging are commonly quoted separately, and the price varies with the filter type and the size of the system — which is perfectly normal. The thing to watch is transparency: a good operator tells you upfront what the base clean covers and what any extras cost, so you can compare quotes like-for-like. Be wary of a very low headline price with no clear breakdown, where the extras only appear on the day. Ask for the inclusions and any optional extras in writing before booking.
3. What brush type do you use for flexible duct?
As covered in our guide on flexible vs rigid ducts, the wrong brush type in flexible duct tears the inner liner. A professional company knows that flexible duct requires a softer brush type and can describe their brush selection approach. An operator who uses the same brush for all duct types, or who doesn’t know that different brush types exist, is a risk for flex duct liner damage.
4. Can you provide a written condition report?
A quality operator produces a written report documenting any duct damage, disconnections, collapsed sections, or mould findings identified during the service. This report is valuable for rental property compliance records and for tracking system condition. An operator who cannot or will not provide any written record of findings beyond the invoice is providing a lower tier of service.
5. Can you provide a certificate of currency for public liability insurance?
Any legitimate Melbourne business performing work on your property should have current public liability insurance. Ask for a certificate of currency — a document from their insurer confirming current coverage. A cash-in-hand operator without insurance has no coverage if they damage your property or cause a personal injury during the work.
Warning Signs to Avoid in Melbourne Duct Cleaning
Suspiciously low prices
As covered in our cost guide, a professional service for a 3 to 4 bedroom Melbourne home should cost $350 to $550. A quote of $99 to $150 for any size Melbourne home cannot cover the cost of professional equipment, an experienced technician, and 2 to 3 hours of labour. These prices indicate a service that is not using professional-grade extraction equipment.
No public liability insurance
Duct cleaning means working on your heating and cooling system and often in the roof space, so a professional operator carries public liability insurance and is happy to confirm it on request. A company that cannot or will not provide proof of insurance is one to avoid — if a duct, ceiling or unit is damaged during the work, you want to know you are covered. Asking “are you insured, and can you confirm it?” quickly separates established operators from fly-by-night ones.
Bait-and-switch pricing
There is an honest version of recommending extra work and a dishonest one — know the difference. A good operator will sometimes identify genuine additional issues during inspection or cleaning — a damaged or disconnected duct, a failing filter, heavy contamination — and recommend further work. That is legitimate when the findings are documented in a written condition report, explained to you, and offered as your choice to accept or decline. The red flag is bait-and-switch: a suspiciously low price to win the booking, then pressure to pay much more for vaguely described “severe contamination” or “dangerous mould” with no report, no evidence and no option to decline. If extra work is recommended, ask to see it documented — and remember you can always take time to decide or seek a second opinion.
No physical address or ABN
A registered Melbourne business has a verifiable ABN (searchable at abr.business.gov.au) and a physical business address. A company with only a mobile number and a generic email address has no verifiable business presence — no accountability if the work is inadequate.
Getting an Accurate Quote from a Melbourne Duct Cleaner
To get an accurate quote (rather than a low-ball number that changes on arrival), provide the following information to any company you contact:
- Number of supply registers (count them before calling)
- System type: gas heating, evaporative cooling, ducted reverse-cycle, or combination
- Home size in bedrooms or rough square metres
- Approximate year of construction (helps assess likely duct type and condition)
- Whether the system has been professionally cleaned before and when
- Any known problems: musty smell, weak airflow from specific registers, visible mould at vents
A company that gives a firm price without asking any of these questions is either using a blanket flat-rate system or is not thinking carefully about what the job involves.