When a bathroom exhaust fan fails or can no longer keep the room dry, replacing it is usually more sensible than repairing it — and it is the ideal moment to fix any underlying ducting or sizing problems at the same time. This guide covers when to replace, how to choose the right fan, what it costs in Melbourne in 2025, and the upgrade options worth considering while the technician is there.
When to Replace a Bathroom Fan
Replace a bathroom exhaust fan when:
- The motor has failed — the fan hums but won’t spin, is dead, or cuts out from overheating. Motor failure is the usual end-of-life signal.
- It is grinding or squealing — worn bearings inside the motor that cannot be cleaned or tightened away.
- It can’t keep the room dry — persistent condensation or mould despite the fan running, where the fan is undersized or cannot be ducted properly in its current form.
- It is old and noisy — an ageing axial fan that is loud and weak is worth upgrading to a modern quiet unit.
- You want a timer, humidity sensor or heat — a replacement is the chance to add these features.
Repair vs Replace
The repair-versus-replace decision for a bathroom fan is simpler than for larger appliances, because the part that usually fails — the motor — is integral to the unit and rarely economical to replace on its own. When the motor goes, replacing the whole fan typically costs little more than a motor repair would, and gives you a new unit with a warranty.
Repair makes sense only for faults that are not the motor: a loose cover or housing causing rattle, a dust-clogged impeller cutting airflow, a duct problem, or a switch or timer fault. These can be put right without replacing the fan. If the fan body and motor are sound and only the ducting is at fault, fixing the duct is the right call. But once the motor is failing, replacement is the practical choice — and a chance to improve on what was there.
Choosing the Right Replacement
The key choices when selecting a replacement bathroom fan are:
Type
A quality centrifugal ceiling fan is the standard upgrade from a basic axial unit — quieter and stronger through a duct. An inline fan, with the motor in the roof cavity, is the quietest and most powerful option, ideal for large bathrooms or long duct runs. See our guide to fan types.
Airflow
Match the fan to the room. AS 1668.2 sets 25 L/s minimum for a bathroom, but choose with margin above that to allow for ducting losses — a real 25 to 40 L/s for a standard bathroom, 40 to 60 L/s for a large one.
Features
Consider a built-in run-on timer or humidity sensor for reliable moisture clearing, and a 3-in-1 light/heat/fan unit if you want warmth in a cold Melbourne bathroom — checking its exhaust rating is adequate.
Replacement Cost Melbourne 2025
| Scenario | Complete Price (AUD) | Notes |
|---|---|---|
| Like-for-like replacement (wiring & duct exist) | $250 – $480 | Minimum call-out; price set by fan chosen |
| Replacement + new duct to roof cowl | $450 – $750 | Fixes a fan that vented into the roof |
| Upgrade to inline fan (large bathroom) | $650 – $1,400 | Motor in roof — quiet and powerful |
| Add run-on timer or humidity sensor | $250 – $400 | Complete job — licensed electrical work |
| 3-in-1 fan / light / heat unit replacement | $350 – $650 | Depends on unit and existing wiring |
All prices are complete-job prices including the fan, labour and call-out. FreshDuct provides upfront pricing before any work begins. Call 0431 918 137.
Upgrade Options Worth Considering
Since the technician is already there and the fan is being changed, a few upgrades are worth considering at the same time, because doing them together avoids a second call-out:
- Proper ducting to the roof: if the old fan vented into the roof cavity, fix it now — this is the single most valuable improvement.
- Run-on timer or humidity sensor: ensures the fan runs long enough to clear moisture without relying on memory.
- A quieter, stronger fan: upgrade from a noisy axial unit to a centrifugal or inline fan.
- Correct sizing: if the old fan was undersized, fit one that actually matches the room.
What the Replacement Involves
- Assessment: the technician confirms the fan location, existing wiring and ducting, the discharge path, and the right replacement unit.
- Isolation: power to the fan circuit is safely isolated before work begins.
- Removal: the old fan is removed from the ceiling opening and disconnected.
- Fitting: the new fan is fitted into the opening (adapted if needed), connected to the wiring, and connected to the duct.
- Ducting check: the technician confirms the fan discharges to the outside — adding or correcting ducting and the roof cowl if required.
- Test: the fan is tested for correct operation, airflow and any timer or sensor function before completion.
A straightforward replacement is a same-visit job, typically one to two hours. Call FreshDuct on 0431 918 137 to book.