Best Electric Instant Hot Water for Apartments and Units
The best hot water system for an apartment depends on one question nobody checks before they ring us: is there 3 phase power in the unit?
The best hot water system for an apartment with 3 phase power is the Stiebel Eltron DEL 18 Plus at $1,365. It is a 19.4 kW electric instantaneous unit the size of a shoebox (466 x 225 x 116mm, 3.2 kg), it caps output at 50°C so no tempering valve is needed, and it replaces a tank that is eating half a cupboard. In Melbourne, Canberra or a unit with two bathrooms, go to the 28 kW DEL 27 Plus at $1,399.
If your apartment only has single phase power, the honest answer is different, and it is further down. Do not skip it.
Want your exact size? Our instant hot water sizing calculator works out the kW or litres a minute you need in winter, checks single or 3-phase power, then shows the units that fit.
Our picks for apartments and units
The Stiebel Eltron DEL 18 Plus is the best all round apartment hot water system, and the DEL 27 Plus, DHB-E 18 LCD and DHC-E 8 range cover colder cities, tighter budgets and single phase units.
- Best overall: Stiebel Eltron DEL 18 Plus, $1,365. 19.4 kW, 3 phase, 27A, 50°C max output. One shower in Brisbane, Sydney or Perth with room to spare. View the DEL 18 Plus →
- Best for cold cities or two bathrooms: Stiebel Eltron DEL 27 Plus, $1,399. 28 kW, 3 phase, 38.9A, 7 year parts and labour domestic warranty. View the DEL 27 Plus →
- Best budget 3 phase: Stiebel Eltron DHB-E 18 LCD, $1,139. 19.4 kW, LCD temperature control from 20 to 60°C. View the DHB-E 18 LCD →
- Single phase, kitchen or laundry: Stiebel Eltron DHC-E 8/60, $915. 9.5 kW on 240V, sits under the sink. View the DHC-E 8/60 →
Prices current as of October 2026, AUD including GST, unit only. Installation not included.
Apartment hot water units compared
The table compares every electric instant unit that suits an apartment, by power supply, output, current draw and price.
| Unit | Supply | Output | Current | Max temp | Best for | Price |
|---|---|---|---|---|---|---|
| DEL 18 Plus | 3 phase | 19.4 kW | 27A | 50°C | 1 bathroom, warm cities | $1,365 |
| DEL 27 Plus | 3 phase | 28 kW | 38.9A | 50°C | Cold cities, 2 bathrooms | $1,399 |
| DEL 13 Plus | 3 phase | 14.5 kW | 20.2A | 50°C | Studios, low flow showers | $1,259 |
| DHB-E 18 LCD | 3 phase | 19.4 kW | 27A | 60°C | Budget 3 phase | $1,139 |
| DHE 18 AU | 3 phase | 19.4 kW | 27A | 60°C | Exact temperature control | $1,415 |
| DHC-E 8/60 | Single phase | 9.5 kW | 40A | 60°C | Kitchen, laundry | $915 |
Prices current as of October 2026. Specs from the Stiebel Eltron technical data on each product page.
Check your power supply first
Your apartment's power supply decides which electric instant hot water unit you can run: 3 phase units like the DEL 18 Plus need a 3 phase supply to the unit, and single phase apartments top out at 9.5 kW.
Look at the switchboard. Three main switches ganged together, or a meter marked 3 phase, usually means you have it. One main switch usually means single phase. Plenty of newer apartment buildings run 3 phase to each unit; most older walk ups do not. If you are not sure, ask a licensed electrician or your strata manager before you buy anything. Our explainer on single phase vs 3 phase instant hot water goes deeper.
Best overall: Stiebel Eltron DEL 18 Plus
The Stiebel Eltron DEL 18 Plus is the best hot water system for most 3 phase apartments, because 19.4 kW covers a winter shower in Brisbane, Sydney and Perth and only just short of it in Melbourne, for $1,365.
One standard shower at 40°C in winter needs about 15 kW in Brisbane, 17 kW in Sydney and 19 kW in Melbourne. The DEL 18 Plus clears the first two easily. It draws 27A per phase, switches on at 2.5 litres a minute, is WaterMark approved, and electronically limits output to 50°C, which is the bathroom limit in Australia. Made in Germany.
Why it suits apartments: it is 116mm deep. It mounts on the wall inside the old tank cupboard, under a vanity or in the laundry, and the cupboard becomes storage again.
Best for cold cities or two bathrooms: Stiebel Eltron DEL 27 Plus
The Stiebel Eltron DEL 27 Plus is the best apartment hot water system for Melbourne, Canberra, Hobart, or any unit where two people shower back to back, at $1,399 for 28 kW.
Canberra needs about 21 kW for one winter shower, and 28 kW gives roughly 13 to 17 litres a minute of warm water depending on the city. The catch is the current: 38.9A per phase. Your electrician must confirm the apartment's supply and the building's capacity can carry it. It comes with a 7 year parts and labour domestic warranty, ECO mode and a display showing the set temperature.
Two showers running at the same time is beyond any electric instant unit in a cold city. That is gas territory, and most apartment buildings make gas hard.
Best budget 3 phase unit: Stiebel Eltron DHB-E 18 LCD
The Stiebel Eltron DHB-E 18 LCD is the cheapest good 3 phase apartment hot water unit, giving the same 19.4 kW as the DEL 18 Plus for $1,139.
The difference is control. The DHB-E sets temperature on an LCD from 20 to 60°C, so for a bathroom the installer must make sure delivered water stays at or under 50°C. The DEL Plus caps itself at 50°C out of the box. For an investment unit where you want the lowest price on a reliable German heater, the DHB-E is the one.
Single phase apartments: the honest answer
A single phase apartment cannot run a full winter shower on an electric instant unit, because the biggest single phase unit is 9.5 kW and that gives only about 5 litres a minute of 40°C water in a Sydney winter.
Five litres a minute is a weak shower. Some people live with it in Brisbane with a low flow head. Most do not. If you have single phase and want a proper shower, your realistic options are to keep a storage tank, ask strata about upgrading the unit to 3 phase, or use gas where the building allows it.
Where single phase instant does work brilliantly is the kitchen and laundry. The DHC-E 8/60 sits under the sink, 360 x 200 x 110mm, and gives hot water in seconds instead of running cold water down the drain waiting for a far tank. The 50°C bathroom version, the DHC-E 8/50, is currently sold out; contact us for the restock date. More on this setup in our point of use hot water guide.
What about gas in an apartment
Gas continuous flow hot water works in apartments only when the building has a gas supply and the unit can be flued or mounted outside, which strata often restricts.
Where it is allowed, a gas unit beats electric for two showers at once. The Midea M Series M26 internal ($1,569) is built for indoor installation with a flue, and the external Midea M20 ($749) suits a balcony wall where permitted. Both carry a 5 year residential warranty and must be installed by a licensed gas fitter. Check the strata by laws before you buy either.
Replacing an apartment hot water tank with instant
Replacing an apartment hot water tank with an electric instant unit means a new dedicated circuit from the switchboard, a plumber to repipe at the old tank location, and usually strata approval for any switchboard work.
The unit is the cheap part. Budget for the electrician first, because the circuit and any board upgrade decide whether the job is simple. Our guide to replacing a hot water tank with instant lists every change.
Frequently asked questions
What is the best hot water system for an apartment in Australia?
The best hot water system for an apartment in Australia with 3 phase power is the Stiebel Eltron DEL 18 Plus at $1,365, a compact 19.4 kW electric instant unit that caps output at 50°C. In Melbourne, Canberra or a two bathroom unit, the 28 kW DEL 27 Plus at $1,399 is the better pick (prices as of October 2026).
Can I install instant hot water in a single phase apartment?
Yes, but a single phase apartment is limited to about 9.5 kW, which gives roughly 5 litres a minute of 40°C water in a Sydney winter. That suits a kitchen or laundry well, but most people find it too weak for a shower.
Do I need strata approval for a new hot water system in a unit?
Usually yes for any change to the switchboard, the building's electrical supply, gas or external flues, and many strata schemes want to know about plumbing work too. Check your by laws and ask the strata manager before you buy.
How much space does an electric instant hot water unit need?
An electric instant hot water unit like the Stiebel Eltron DEL 18 Plus measures 466 x 225 x 116mm and weighs 3.2 kg, so it mounts on a wall inside a cupboard or under a vanity. It frees up most of the space a storage tank used.
Is electric instant hot water expensive to run in an apartment?
Electric instant hot water costs about 75 cents for an 8 minute Sydney winter shower at 33 cents per kWh, as of October 2026. Apartments with one or two people usually find it cheaper overall than a tank, because nothing heats when nobody is using water.
Not sure what your apartment can run?
Send us a photo of your switchboard, your city, the number of bathrooms and how many people live there. We will tell you which unit fits, or tell you straight if your power supply will not run one.
Ask us which unit suits your apartment →
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This guide is general information for Australian households and is not a substitute for advice on your specific apartment and building. Electric instantaneous water heaters must be installed by a licensed electrician and plumber, on a dedicated circuit sized to the unit. 3-phase units need a 3-phase power supply, and any supply upgrade must be arranged through a licensed electrician, your network provider and, in strata buildings, the owners corporation. Gas continuous flow units must be installed by a licensed gas fitter, and the 70°C preset Midea models need a tempering valve. Confirm final sizing with us or your installer before you buy.