DHE 18 AU / DHE 27 AU

  • Made in Germany
  • Precise hot water temperature up to 60°C with 4i Technology
  • Electronically controlled to accurately regulate the output water temperature, compensates for fluctuations in pressure and temperature changes
  • Can accept pre-heated water (up to 55°C), e.g. for preheating with a solar heating system
  • Compact space saving design for installation flexibility
  • No safe tray, flue or ventilation required
Ask Quick Question

Product Overview

The DHE AU instant water heaters deliver hot water with precision. Comfort is the number one priority as the DHE AU 18 and DHE 27 AU deliver hot water exactly to the degree. Utilising 4i Technology, the intelligent fully-electronic water heater compensates for fluctuations in pressure and temperature and using its series of sensors it precisely regulates the hot water output. This ensures that you get your requested hot water temperature to the degree.
Available at:
Or your local plumbing supply store.

Product Details

Made in Germany, high quality design from STIEBEL ELTRON.

  • Accurate delivery of the required hot water temperature, the DHE automatically adjusts flow to precisely deliver the selected temperature
  • Electronically controlled to accurately regulate the output water temperature, compensates for fluctuations in pressure and temperature changes
  • Bare wire element complete with pressure-tested copper casing is suited to both soft and hard water areas
  • Electronic safety system with air detection
  • Memory function and shower functions
  • WaterMark approved, licence number WMKA00301, AS3498
  • Temperature selection between 20-60° Celsius
  • Pre-heating capabilities: can accept pre-heated water (up to 55°C), e.g. for reheating with a solar heating system

Installation flexibility

  • Compact space saving design for installation flexibility
  • No safe tray, flue or ventilation required

Efficiency monitoring

  • Easy to read backlight display, changes from amber to green when operating in an ECO mode
  • Display showing the current water and energy consumption
  • Economy monitor shows energy, water and CO2 savings compared to a hydraulic instantaneous water heater

Available in two electrical sizes:

  • DHE 18 AU - 19.4kW, 27 Amps per phase, three phase 415V
  • DHE 27 AU - 29.1kW, 40 Amps per phase, three phase 415V


  • 5 year full parts and labour domestic warranty*

*Conditions apply - refer to warranty policy for full details.

Technical Data

Model number DHE 18 AU DHE 27 AU
Rated output (415V) 19.4kW 29.1kW
Rated current (415V) 27Amp 40Amp
Phases 3/PE 3/PE
Electrical installation As per AS/NZS3000
Installation requirements AS/NZS3500.4.2 & local requirements
Switch on flow rate (minimum flow rate required to switch on the water heater) 2.5L/min 2.5L/min
Permissible operating pressure 1000kPa 1000kPa
Temperature adjustment 20-60°C 20-60°C
IP Rating IP25 IP25
Height 478mm 478mm
Width 225mm 225mm
Depth 105mm 105mm
Weight (filled with water) 4.9kg 4.9kg
Colour white white
Nominal capacity 0.4L 0.4L
Approvals WaterMark Lic No. WMKA00301, AS3498
For one/several draw off points Yes/Yes Yes/Yes
Heating system Bare wire Bare wire
Electronic flow rate control Yes Yes
Electronic air detection system Yes Yes
Accepts pre-heated water (solar) Yes (incoming hot water must not exceed 55°C)
Programmable temperature Yes Yes
Wellness shower programs 4 4
ECO energy & water function Yes Yes


File Category Type Download
DHE Data SheetData SheetPDF
866.31 kB
DHE AU Operation InstallationOperation and Installation GuidePDF
12.22 MB
DHE AU WarrantyWarrantyPDF
109.72 kB
1.13 MB
Revit File of STIEBEL ELTRON's DHE AUTechnical DrawingRFA
396.00 kB
STIEBEL ELTRON Tech Line Drawing DHE AUTechnical DrawingJPG
1.15 MB
Model & Serial Number LocationSerial Number LocationPDF
141.08 kB


1. How do I know if I have 3 phase power available at my property?

Contact your local energy provider and inform them of your address. They will be able to let you know if you have 3 phase power available at your address.

2. I have 3 phase power at my property, can I install a DHE instant hot water system?

You will need to check with your electrician to find out how much 3 phase power is available in "Amps per phase". The DHE 18 AU water heater requires 27 Amps per phase, whereas the DHE 27 AU requires 40 Amps per phase.

3. I have a 3 phase electric instantaneous unit I want to replace, what STIEBEL ELTRON system should I select?

You will need to confirm the amperage supply to the hot water unit from the circuit breaker in the switchboard. Please contact us to confirm the appropriate instantaneous electric hot water system.

4. What size instantaneous electric water heater do I need for my apartment or house?

As a general rule, the instant hot water system required will be based on the number of hot water outlets the hot water system needs to service, along with the incoming cold water temperature. As a general guide in an apartment/house with 1 bathroom, a 19.4kW three-phase electric instantaneous water heater (e.g. DHE 18 AU, DEL 18 AU or DHB-E 18 AU) is suitable. In a house with 2 bathrooms, a 28-29.1kW three-phase electric instantaneous water heater (e.g. DHE 27 AU, DEL 27 AU or DHB-E 27 AU) should be selected.

5. How can I tell if I have a DHE 18 AU or a DHE 27 AU?

Underneath the dial that adjusts the temperature there is a flap that pulls forward and then drops down. A rating label is located up under the flap showing the model and size - DHE 18 AU or DHE 27 AU. Within the downloads section of the DHE you can download a pdf showing you exactly where and how to locate this sticker.

6. What hot water temperature can the DHE AU water heaters deliver?

The DHE 18 AU and DHE 27 AU can deliver hot water at 60°C. If supplying hot water for a domestic bathroom, the plumbing regulations require the installation of a temperature control device to supply water not exceeding 50°C. Alternatively, the STIEBEL ELTRON DEL AU instantaneous electric water heater may be a suitable choice which delivers hot water not exceeding 50°C in accordance with AS3498. Click on the DEL AU product to find out more.

7. Where can the DHE AU instant hot water system be installed?

The water heater can be installed almost anywhere due to its compact size. The water heater does not require ventilation, relief drain or safe trays so it can be installed in a cupboard, in the roof space, below the sink, in a service cavity, in a Euro laundry just to name a few options. If installing outdoors, the hot water system must be protected from the elements by a protective covering such as a meter box.

8. I have an old DHE 21 electric instantaneous water heater but cannot see this model on this website anymore. Can I replace this model?

This DHE 21 is no longer available and has been replaced by the DHE 18 AU three phase electric instantaneous water heater.

9. How far can the water heater be installed from the hot water outlet?

The DHE AU water heaters are designed to be installed as close as practical to the most used hot water outlet. Installing closer to the point of use can help to save water and energy by delivering hot water quickly to the outlet. The STIEBEL ELTRON 3 phase electric instantaneous water heaters are designed to service multiple outlets located several metres away from the system.

10. How efficient is an instantaneous electric water heater compared to an electric storage hot water system?

Compared to a storage hot water unit an electric instantaneous water heater can be up to 30% more efficient. This is due to the water heater not storing any hot water and not incurring heat losses from storing a body of hot water.

11. Where can I purchase a DHE AU water heater?

The DHE AU water heater range is available from all leading plumbing stores.

Ask Quick Question