Benefits include:

You can save up to 80% of your  hot water energy costs when compared with a traditional electric hot water system!  The Sanden Eco® Plus Hot Water Heat Pump uses only 20% of the energy required by older-style, electric element  hot water storage systems.

Not only does a Sanden Eco® Plus heat pump hot water system help save on energy costs, it also delivers:

(a) Heat Pump Unit Benefits:

  • Innovative technology; up to 50% faster heat recovery than currently available Hot Water Heat Pumps.
  • Industry leading quality & performance; the Sanden Eco Plus gives you the highest level of STC credits of any currently available heat pump hot water system.
  • Class leading warranties; backed by Sanden’s 35 years of operation in Australia.


(b)  Stainless Steel Storage Tank Benefits:

  • High quality; extra long life duplex stainless steel cylinder.
  • Fully insulated; for extremely low heat loss.
  • Safety, pressure and temperature relief valves.
  • Mains pressure rated.

What are STCs and how many do you get with your Sanden?

The purchase and installation of a Sanden Eco® Plus Hot Water Heat Pump entitles you to Small-scale Technology Certificates (STCs) – formerly known as Renewable Energy Certificates (RECs). For more information: visit and

The Sanden HWHP achieves the highest level of STCs of any hot water heat pump, currently available in Australia, and these are as below:

To find out which zone your postcode is in click here (note this may change so if in doubt contact the clean energy regulator for more information)

The Table below shows how many STCs are available for each Sanden model in each STC Zone 


How much are STCs worth?

STCs can be priced through the Government's STC clearing house or on the open market at places like Green Energy Markets

So say you bought a Sanden GAU-250EQTB and you lived in zone 5 and the current STC price was $35

The total discount you would receive would be: 34 STCs x $35 = $1,190. 

So you would receive a discount of $1,190 off the total price of your Sanden unit (note this is an example only to illustrate how STCs are calculated the actual discount will vary depending on the current STC price).


The Sanden Eco Plus hot heat pump hot water system is available in the following three sizes:

Tank size/shape No. of persons using hot water Typical dwelling type Suitable for Off-peak & Continuous tariffs? STC rebates available?
160L 2-4 Units / Townhouses Continuous only Yes
250L 3-5 Residential Both Yes
315L 4-6 Residential Both Yes

The Sanden Eco Plus heat pump hot water (HPHW) system is designed to last for 15 years. The high quality, weather resistant Eco® Plus HWHP outdoor module carries a 6 year warranty and the extra-long life stainless steel storage tank carries a class leading, 15 year warranty.

The Sanden Eco Plus heat pump hot water (HPHW) system will operate effectively between - 10 º C and + 43 ° C, without the need for an electric booster element. It is also fitted with built in freeze protection, making it suitable for all climates.

The unit is rated at 37dB (measured at one metre from the unit), which is almost silent. By comparison, a whisper is around 30dB and the sound of the inside of a Library is approximately 40dB.

Getting access to block out timer mode

Note:  After installation only 'maintenance mode' should be used for block out changes.  There is another procedure on page 16 of the installation manual related to the block out timer this only applies when the unit is first installed. 

To set the block out timer for your Sanden unit you will need to access the 'clock control unit' (shown below in blue), to do this you will need to remove the four screws at the side of the top cover panel on your outdoor unit (shown below), which has a 10 mm lip around the entire unit, to access.

Once you have access to the clock control unit you can set the block out (BO) timer by following the steps below, this will allow you to set your block out hours.  

1 - Hold down "UP" and "DOWN" together - gets you to "HSE" mode

2 - Press "UP" - gets you to outlet water temp setting mode

3 - Press "UP" - gets you to BO mode

4 - Press "ENTER" - gets you to EDIT BO mode (then enter the hours accordingly).

For more information consult page (17-22) of your Sanden installation manual which can be found here

Setting the hours you want to block out

The block out time functions using four digits first two digits = off, second two digits = on so:

To set the timer to run between 12 midday (AEST) and 6 pm set the blackout timer to 1812, which means off at 6 pm (18 in 24 hr clock terms) and on at 12 pm. 

To set the black out timer to run off-peak you might choose 0722 which means on at 10 pm (in 24 hr notation) and off at 7 am. Ensure that the off-peak tariff supplies a minimum of 5 hours continuous power to the Sanden HPHW.

If in doubt don't hesitate to contact us at and we can guide you through the process 

Yes, importantly no warranty applies to the heat pump unit and the storage tank, where the chloride level exceeds 200 mg/litre and the pH is less than 6.0. If in doubt, seek water quality information from your local council or water supplier.

No, unlike other competitor heat pump hot water (HPHW) systems, the Sanden Eco® HPHW system does not require an electric booster element

Yesfor efficient processing of warranty claims, should they arise, please register your Sanden Eco® Plus heat pump hot water system here.

Give PureElectric a call 1300 86 78 73 or send us an email and we'll be happy to assist you.

The Sanden Eco® Plus heat pump hot water (HPHW) system operates like a refrigerator in reverse. It contains a fan that forces air through an evaporator that contains a refrigerant. The heat in the ambient air passes through the evaporator (note: even air below 0 º C contains heat energy) and is absorbed by a natural refrigerant, R744 (aka CO2), which is ozone friendly and does not significantly contribute to global warming compared with most other refrigerants (older style refrigerants have thousands of times more global warming impact for the same amount of gas, when compared with CO2).

The warm gaseous refrigerant is circulated in the system via a compressor. As it passes through the compressor, its pressure rises, as does its temperature. This hot refrigerant then passes through a heat exchanger to heat the water, which is finally pumped to the storage tank.

How Heat Pump Hot Water Systems Work

Why does the Sanden use CO2 as its working gas, what is the benefit?

  • There is far less environmental impact (i.e. No ozone layer depletion and minimal global warming) than other commonly used refrigerants, should the system leak. 
  • There is a much higher efficiency, thereby allowing more heat to be transferred to the water, for less energy used (i.e. Excellent  thermodynamic ability).

Isn't CO2 a greenhouse gas and therefor bad for the environment?

While it is true that Carbon Dioxide (CO2) is a greenhouse gas it has a Global Warming Potential (GWP) of 1. Whereas refrigerant gases in other heat pumps can have GWP of over 10,000, which means if they leak to the atmosphere they contribute 10,000 times more to global warming compared with the refrigerant gases used in a Sanden Eco Plus. 

The table below shows the GWP for some common refrigerant gases (note: GWP must include a time interval over which the greenhouse gases act, in this case 100 years)

Environmentally Safe CO2 in Sanden Hot Water Heat Pumps


Our system utilizes less than 1 kg of R744 (CO2) as a refrigerant contained in a closed system at the factory.  The installer does not need to charge the heat pump on site.