Nothing ruins a winter morning like stepping out of a hot shower onto a cold floor. A bathroom heater fixes that cheaply, but a bathroom is a wet area, so where the unit goes and how it vents are governed by rules most quotes never mention.
Pricing agreed before we start. We usually reply the same day.
Bathroom heaters are not expensive and they make a real difference to a winter morning. They also do something less obvious: by driving moisture out of the room they cut the mould and mildew that bathrooms are notorious for, and they stop towels sitting damp all day.
What makes the job more than a swap is the room itself. AS/NZS 3000 treats a bathroom as a wet area and divides it into zones measured out from the bath and shower. The closer to the water, the stricter the rules about what may be installed and how well sealed it has to be. That governs where a heater can sit, where its switch can sit, and what ingress rating the unit needs.
On top of that sits the ventilation side. Since NCC 2022, a bathroom exhaust has to move at least 25 litres per second and discharge to outdoor air. Venting into the roof space, which is how a great many older units were left, is no longer acceptable. If the room has no window, the fan also has to run on after the light goes off.
None of this makes the job hard. It does mean the difference between a unit that clears steam properly for fifteen years and one that quietly rots your roof battens.
Zones are measured from the bath or shower, not from the walls. This is why the right spot for a 3-in-1 is usually not directly above the shower, which is where people tend to assume it belongs.
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How to read it: Zone 0 is inside the shower base or bath itself. Zone 1 is the volume directly above it, up to 2.5 m. Zone 2 runs a further 600 mm horizontally either side. Equipment inside the zones has to be rated for it, so siting the unit clear of them, as shown on the right, is usually both cheaper and better for airflow.
Four common options, and the honest trade-offs between them. Figures are typical rather than exact, since every model differs.
| Type | Typical draw | Best for | Worth knowing |
|---|---|---|---|
| 3-in-1 (heat, exhaust, light) | Around 1,000–1,200 W | Most family bathrooms, and any room short on ceiling space | One cut-out does three jobs, but the exhaust still has to hit 25 L/s and be ducted outside |
| Heat lamps only | Around 275 W per lamp | Instant warmth over a change area | Heats people rather than the room. Cheap to run in short bursts, poor as background heat |
| Fan-forced ceiling heater | 1,000–2,400 W | Larger or colder bathrooms that need the whole room warmed | The heaviest load of the four. Frequently the one that needs its own circuit |
| Heated towel rail | Around 60–150 W | Drying towels, plus gentle background warmth | Hardwired, not plugged in. Add a timer so it is not running twenty-four hours a day |
Underfloor heating sits outside that table because it is a different decision. It gives the most even warmth of anything here and it is invisible, but it needs its own circuit, a floor sensor and a thermostat, and it is dramatically cheaper to run in while a floor is already up. If you are retiling, decide before the tiler starts rather than after.
Beyond the type, the things actually worth weighing are the size of the room, whether you want a timer or thermostat rather than a plain switch, and how the unit will look. Modern units come in enough finishes that you no longer have to accept a beige plastic square in the middle of a renovated ceiling.
If your heater includes a fan, these apply to it. They are the part of the job most often done badly, and the part you cannot see once the ceiling is closed up.
That is the minimum flow rate the NCC sets for a bathroom or sanitary compartment. Plenty of budget units fall short of it once a length of duct is attached, because the quoted figure is usually free air rather than installed performance.
We size the unit for the room and the duct run, not for the number on the box.
Exhaust has to discharge directly or via a duct to outdoor air. Dumping it into the roof space stopped being acceptable under NCC 2022, and it was always a bad idea: warm wet air in a cold roof condenses on the underside of the roofing and the timbers.
If you have ever found damp insulation or black mould above a bathroom, this is usually why.
If the bathroom has no natural ventilation, the exhaust must be interlocked with the light switch and keep running for 10 minutes after the light is switched off.
It is a small addition at install time and a nuisance to retrofit, so it is worth getting right the first time even in rooms that do have a window.
A four-lamp heater is around a kilowatt before the fan and light. A fan-forced unit can be more than twice that. On older homes where one lighting circuit serves half the house, that is often the deciding factor.
We check what the existing circuit is already carrying before quoting, and fit a dedicated circuit where the load calls for it.
The mirror still fogs and the room stays damp
The fan is either undersized for the room or fighting a duct that has sagged, kinked or come off entirely in the roof space. A fan can sound perfectly healthy while moving almost no air.
Worth checking before you blame the unit, because replacing it will not fix a collapsed duct.
The heater trips the safety switch
Moisture in the fitting or its wiring, a failing lamp holder, or a heater sharing a circuit that is already at its limit. Bathrooms are the wettest room in the house, so a fault here deserves attention rather than a reset.
If it trips only when the shower has been running, that is a strong hint at moisture rather than load.
The lamps are warm but the room is still cold
Heat lamps are radiant. They warm whatever they shine on, not the air, so they feel excellent standing under them and do very little for the room as a whole.
If you want the whole bathroom warm, a fan-forced unit or underfloor heating is the right tool, not more lamps.
There is mould in the ceiling above the bathroom
Almost always an exhaust discharging into the roof space rather than outside. The moisture has to land somewhere, and in a cold roof it condenses on the underside of the roofing and soaks the insulation.
Fixing it means ducting the fan out through an eave or a roof cowl, which we do as part of the install.
Kept deliberately simple, because most of the value is in getting the decisions right before anyone cuts a hole.
We look at the room, the ceiling space above it, the existing circuit and where the duct can realistically run. Then we tell you which type suits the room and give you a fixed price. Decades of these installs means that conversation is usually short.
Access from a stepladder or from above, the cut-out prepared, the unit mounted clear of the wet zones, wiring run back to a suitable circuit, and the exhaust ducted out through an eave or cowl rather than left loose in the roof.
We test that it performs, walk you through using it, and clean up so the room looks as it did before we arrived. You get a Certificate of Compliance for Electrical Work for the job, which is your record that it was tested and complies.
Electrical wiring work in NSW must be carried out by or under the supervision of a licensed electrician. A ceiling heater sits in the wettest room in the house, carries a real load, and usually shares a circuit with something else, which is a poor combination for a confident afternoon with a YouTube video.
The work also has to be certified. Your electrician lodges a Certificate of Compliance for Electrical Work confirming the installation was tested and complies with the Gas and Electricity (Consumer Safety) Regulation 2018 and the relevant standards, within 7 days of testing. Since 1 July 2026 that is lodged through the BCNSW eCert portal.
Keep that certificate. It is what you hand a buyer, an insurer or a building inspector when they ask who did the work and whether it was tested.
No. AS/NZS 3000 divides a bathroom into zones measured from the bath or shower, and what you can install gets stricter the closer you get to the water. Zone 0 is inside the bath or shower basin itself. Zone 1 is the volume directly above it, up to 2.5 metres. Zone 2 extends 600 mm horizontally beyond Zone 1. Most 3-in-1 units are sited clear of those zones, which is usually toward the middle of the room rather than over the shower. Where a unit does have to sit inside a zone it must carry the ingress protection rating for that zone, and plenty of cheaper units do not.
Only if it moves enough air and is ducted properly. Under NCC 2022 a bathroom exhaust must achieve at least 25 litres per second, and it has to discharge directly or via a duct to outdoor air. Venting into the roof space is no longer permitted, which catches out a lot of older installations. If your bathroom has no window or other natural ventilation, the exhaust also has to be interlocked with the light switch and run on for 10 minutes after the light is turned off.
Usually one of three things. The fan is undersized for the room, the flexible duct has sagged or come adrift in the roof, or there is no duct at all and it has simply been dumping moist air into your roof space for years. That last one is worth checking even if the fan seems to work, because it is what rots roofing timbers and grows mould in the ceiling.
It depends on the unit and what is already on the circuit. A four-lamp heater draws roughly a kilowatt before you add the fan and the light, and a fan-forced ceiling heater can draw more than twice that. On an older home where the lighting circuit is already carrying half the house, a dedicated circuit is often the sensible answer. We check what the existing circuit is doing before quoting rather than assuming.
Both are hardwired rather than plugged in, and both belong on a switched circuit with the switch outside the wet zones. Towel rails are modest, generally under 150 watts, so they rarely cause a capacity problem. Underfloor heating is a different matter: it needs its own circuit, a floor sensor and a thermostat, and it is far cheaper to install while the floor is up than after.
Attending your job is a chargeable callout. We confirm what it costs when you book, and the price for the work itself is agreed before we start, so there are no surprises on the invoice.
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