The Conduction Company fits and replaces bathroom heaters across Auckland: heat lamps, 3-in-1 heat-light-fan units, wall heaters, heated towel rails and underfloor heating. This guide to bathroom heating in NZ compares them on warmth, running cost, price and the wiring rules, using The Conduction Company's own jobs.
In an existing bathroom, The Conduction Company's first choice is a wall heater mounted high, with a separate in-line extractor fan. Heat lamps add instant warmth from above as you step out of the shower. The 3-in-1 heat, light and fan unit is the one it steers away from, because the fan usually fails first.
Heat lamp vs heater: what is the difference?
A heat lamp warms you, and a heater warms the room. That is the short version from The Conduction Company. Here is how the five common bathroom options compare.
Heat lamp. An infrared bulb in the ceiling that warms whatever it shines on, straight away. It is a radiant heater: it heats you, not the air. Good for the minutes after a shower, but it does little for a cold room, and the lamps wear out and need replacing.
3-in-1 heat, light and fan unit. Heat lamps, a light and an extractor fan in one ceiling unit, usually on a three-gang switch. One hole in the ceiling, but the fan sits right beside the hot lamps. In The Conduction Company's experience the fan is usually the part that fails first.
Wall heater. A fan heater: a fan blows air over an element and warms the whole room. Plug-in electric fan heaters, and ceramic space heaters with a fan, work the same way. The Conduction Company mounts wall heaters high on the wall, away from the damp areas, on their own labelled switch.
Heated towel rail. It dries towels and takes the chill off, but it is not a room heater. Heirloom, an Auckland maker, lists its ladder rails at 37 to 253 watts. Consumer NZ puts a plug-in heater at 2,000 to 2,400 watts.
Underfloor heating. Heating cables under the tiles warm the floor from underneath. The Conduction Company calls it the most luxurious way to heat a room, but not the cheapest to run.
What type of heater is best for a bathroom?
For most bathrooms, The Conduction Company's answer is a wall heater for the room, plus a separate in-line fan and downlights. "In a new bathroom, we'll tend to stay away from heat light fan units, going for separated systems, where you've got an inline fan and a couple of recessed downlights and a wall heater," says Jordan Statham, director of The Conduction Company.
The reason is the fan. In a 3-in-1 unit, "the fan unit is typically what fails first, and a lot of the time it's because it's been subject to excess heat because it's so close to the heat lamp," Jordan says. When the fan goes, the whole unit has to be replaced.
Heat lamps still earn their place. In bathrooms that run cold, The Conduction Company adds a heat-and-light unit over where you dry off, and runs it with the wall heater.
In a new or renovated bathroom, The Conduction Company rates underfloor heating the best way to heat the room. It has to go in while the bathroom is being built.
What should replace a 3-in-1 heat light fan unit?
The Conduction Company swaps a failed 3-in-1 for a heat-and-light unit with a duct port, and adds a separate in-line extractor fan. You keep the heat lamps. The new fan is stronger and quieter, and if it ever fails it can be replaced on its own. The Conduction Company replaces a failed unit rather than repairing it, because in most cases it finds the unit cannot be repaired, or fails again soon after. Its job records show 31 jobs replacing or fitting heat, light and fan units since April 2023.
What is a good small heater for a bathroom?
For a small bathroom or ensuite, The Conduction Company typically fits a 1 to 2 kW wall heater. That is a lower wattage than the standard 2.4 kW size, and "perfect for a small bathroom," says Jordan Statham.
If you do not like the look of a wall heater, The Conduction Company has also fitted IP-rated infrared heaters. Each is a small, white rectangular panel on the ceiling that gives off short-wave infrared heat. "They're really nice looking and fully IP rated for bathrooms," Jordan says. Underfloor heating looks best of all, but it needs to go in while the bathroom is being built or renovated.
How much is a bathroom heater?
We quote on facts, not guesses
Before we give you a price, we carry out a proper assessment of your property and how you'll use your bathroom heating.
That way you know exactly what you're buying and the total cost, with no surprises.
Clear expectations from the outset, start to finish.
The estimates below are for standard installation of bathroom heating. The Conduction Company confirms final pricing after a property assessment.
These figures are the middle half of completed Auckland jobs in The Conduction Company's records since 2023.
Wall heater. On The Conduction Company's completed jobs, a wall heater costs about $390 to $750 including GST.
3-in-1 heat, light and fan unit. On The Conduction Company's completed jobs, replacing one costs about $400 to $800 including GST.
The Conduction Company does not recommend fitting a new 3-in-1 unit. It steers clients towards separated systems instead: separate downlights, a separate in-line extractor fan, and a separate heater, such as a wall heater or an in-line heater. The reason is how long they last. "Separated systems can last about double the amount of time or triple," says Jordan Statham, director of The Conduction Company. When one part of a 3-in-1 fails, the whole unit is replaced. With separate parts, a wall heater that fails is replaced on its own, which costs less.
Heated towel rail. On The Conduction Company's completed jobs, a towel rail costs about $200 to $490 including GST.
Heat lamp jobs range too widely for a typical figure, from a bulb swap to a new unit. A separate in-line fan is priced in The Conduction Company's guide to what an extractor fan costs to install.
How much electricity does a bathroom heater use?
A bathroom wall heater draws up to 2.4 kW, around 10 amps, which The Conduction Company says is the largest standard size. A heat lamp draws far less: 275 watts a lamp on the two-lamp units Voltex and HPM sell. The Conduction Company has costed both at 41.30 cents per kWh including GST, MBIE's modelled price for Auckland Central at 15 August 2026. These are worked examples, not a measurement of your home.
Wall heater, 2.4 kW. About 99 cents an hour including GST, or about 33 cents including GST for a 20-minute run around a shower, on The Conduction Company's sums.
Heat lamps. About 11 cents an hour including GST for each 275 watt lamp, so about 23 cents an hour for a two-lamp unit, on The Conduction Company's sums.
Heated towel rail. On The Conduction Company's worked example, a 100 watt rail left on all the time costs about $30 a month including GST, and about $5.02 including GST on a four-hour timer.
More loads are costed in The Conduction Company's guide to what uses the most power in a house.
Do bathroom heat lamps use a lot of electricity?
No, not next to a wall heater, says The Conduction Company. One 275 watt heat lamp draws about a ninth of what a 2.4 kW wall heater does, and a two-lamp unit about a quarter. The catch is that heat lamps warm you, not the room, so they do not replace a heater in a cold bathroom.
What is the best way to heat a cold bathroom?
Preheat it. The Conduction Company advises starting the heater and the extractor fan 5 to 10 minutes before you turn on the shower. Warm air carries more moisture, so the steam stays in the air and the fan pulls it out, rather than it condensing on the windows and walls. Damp air is also harder to heat, so a heater switched on just before a shower struggles to lift the temperature, especially with a ceiling fan pulling the warm air out.
Keep the heater on during your shower or bath if you like. Then switch it off and leave the extractor fan running, on its own or on a run-down timer. How long you run it is up to you.
A bigger wall heater rarely helps, because 2.4 kW is already the largest standard size. In bathrooms that stay cold, The Conduction Company adds a heat lamp over where you dry off and runs both together. For more heat again, it can fit higher-powered options, such as infrared panels. A towel rail will not do the job on its own.
Underfloor heating is the other route, and The Conduction Company fits electric underfloor heating under tiled floors. Run it on a timer or a schedule. Left on all day, "it is going to cause real problems to your power bill," says Jordan Statham of The Conduction Company.
Can I use a regular light bulb as a heat lamp?
No. A heat lamp is an infrared bulb made to give off heat, and an ordinary light bulb is made to give light, says The Conduction Company. Fit the lamp the unit is rated for. HPM, for example, sells its 275 watt replacement lamp as "suitable only for use in bathroom heaters designed for 275W heat lamps".
What is the safest heater for a bathroom?
The Conduction Company's choice is a fixed heater, mounted high on the wall away from the damp areas, on its own switch, and not on a recall list. WorkSafe also advises that plastic-bodied wall-mounted fan heaters in bathrooms should not be left running unattended.
With young children, underfloor heating is the safest choice, says The Conduction Company, but it has to go in when the bathroom is built. In an existing bathroom, it recommends a wall heater mounted high, switched from beside the door with the light switch. Children can turn it on easily, but in most cases cannot reach or touch it, and the clearances are worked out when it is installed. An in-line tempering heater is a less common choice, but "a really decent solution," Jordan says.
Are heat lamps a fire hazard?
They can be. The Conduction Company has seen heat lamps cause significant melting of the PVC parts around them, which is a fire risk. The more common problem is the fan in a 3-in-1 unit. It sits so close to the heat lamps that the heat wears out its motor, so the fan is usually the first part to fail, and then the whole unit has to be replaced. That is why The Conduction Company stays away from fitting 3-in-1 units. When it replaces one, it fits a heat-and-light unit with a separate fan port, and an in-line fan.
Can you use a fan heater in the bathroom?
Yes. The Conduction Company recommends wall-mounted fan heaters for bathrooms, and says they work really well. A plug-in heater is a different question. A standard oil heater is fine in a standard bathroom, says The Conduction Company. If the bathroom has a bath, it recommends against anything plug-in, because of the risk of electric shock, especially without RCD protection or in an older bathroom with an older switchboard.
Bathroom heater recall NZ: which models should you check?
Check the model number on your heater against two notices, The Conduction Company advises. WorkSafe has prohibited Goldair wall-mounted fan heaters with model number 3108 or 3109 on the back, after fires. WorkSafe says to turn them off at the wall and stop using them.
MBIE also has an active recall on the Serene S2068 bathroom heater. The EWRB reports about 16,000 removed from homes and 19 known fires. The Conduction Company removes recalled heaters and fits a replacement.
What are the bathroom heater regulations in NZ?
Three rules in AS/NZS 3000, New Zealand's wiring rules, decide how a bathroom heater is wired, The Conduction Company notes.
Its own switches. A permanently connected room heater needs its own isolating switch and its own on-off switch (clause 4.9.1). The isolating switch goes right beside an entrance to the room, inside the room, or on the switchboard (clause 4.9.2). The Conduction Company wires a wall heater to its own labelled HEAT switch.
RCD protection for 3-in-1 units. For RCD purposes, AS/NZS 3000 counts a combined fan, light and heater unit as a lighting point. So a new circuit feeding one needs 30 mA RCD protection (clause 2.6.3.3.1). The rule covers complete new circuits, not every change to an old one. The Conduction Company's guide to RCD safety protection covers the rest.
RCD protection for underfloor heating. Every heating cable needs 30 mA RCD protection (clause 4.10.5), The Conduction Company notes.
Is lighting cable suitable for a bathroom heat light fan unit?
It can be, depending on the unit's wattage and what else the circuit already supplies, says The Conduction Company. AS/NZS 3008, the cable selection standard, starts by working out the current the circuit has to carry, and the cable must carry it. So The Conduction Company reads the unit's rating plate, not the shop listing, and checks the circuit before reusing the cable. One New Zealand online listing gave a 3-in-1's heater as 2,200 watts in its description and 1,045 watts in its specification table.
A wall heater is different. On The Conduction Company's jobs it takes power from a lightly loaded power circuit nearby, or straight from the switchboard.
Can a heat lamp go above the shower in NZ?
It depends on which shower zone the unit sits in and its IP rating, says The Conduction Company. The Conduction Company's guide to bathroom zones and IP ratings in NZ sets out the heights and ratings. A 3-in-1 unit on a new circuit also needs the RCD protection above.
What makes a heat light fan unit keep tripping the breaker?
Most often it is moisture, says The Conduction Company. The device tripping is usually an RCD or RCBO in the switchboard, and it trips on earth leakage. Moisture builds up inside the heat light fan unit and reaches the live terminals, making a small bridge to the unit's metal parts. A small current then trickles to earth. An RCD is made to cut the supply when current flowing to earth passes a set level (AS/NZS 3000 clause 1.4.102), so it treats that trickle as a possible electric shock and switches off.
Can I replace a bathroom heater myself?
The Conduction Company strongly recommends against it. A wired-in heater is fixed wiring in a wet room, mistakes are dangerous, and most inspectors will not sign off a homeowner's work. As a hard rule, The Conduction Company does not test, certify or connect a homeowner's wiring. It may help only where finished work has left a client stuck, and that takes a thorough inspection and often rework.
In short
A wall heater warms the room, a heat lamp warms you, and a towel rail mostly dries towels. In a renovation, The Conduction Company rates underfloor heating the best option. In an existing bathroom, its usual answer is a wall heater mounted high on its own switch, a separate in-line extractor fan, and a heat lamp where a bathroom runs cold. It steers away from 3-in-1 units, because the fan usually fails first and the whole unit then has to be replaced. The prices here come from The Conduction Company's own completed Auckland jobs and are confirmed after a property assessment.
Frequently asked questions
Are heat lamps still used in bathrooms?
Yes. The Conduction Company still fits heat-and-light units, often beside a wall heater, and swaps failed 3-in-1 units for a heat-and-light unit with a separate in-line fan.
Is a heat lamp safe indoors?
Yes, when it is a ceiling heat lamp made for bathrooms and wired in by an electrician, says The Conduction Company. It has seen heat lamps melt the PVC parts around them, so replace a worn or damaged unit rather than patching it.
What is the best bathroom heater in New Zealand?
The Conduction Company does not rank brands. The bathroom fan heater it fits most often is a Weiss wall heater, mounted high on the wall on its own switch.
How much does bathroom underfloor heating cost?
The Conduction Company quotes bathroom underfloor heating after seeing the bathroom, so there is no typical figure. It is best done while the bathroom is being built or renovated.
Can you replace a heat lamp bulb with a regular bulb?
Not if you want heat. An ordinary bulb gives light, not heat, so the unit stops warming you, says The Conduction Company. Fit the heat lamp the unit is rated for.
What is the safest portable heater for a bathroom?
In a standard bathroom, a standard oil heater is fine, says The Conduction Company. If the bathroom has a bath, it recommends against any plug-in heater, especially without RCD protection.
