Sanden GAUS 250 FQS Heat Pump

Sanden GAUS 250 FQS Heat Pump. Ideal for average Households.

The Sanden Eco® system is the most energy efficient hot water heat pump currently available on the market. As such, when you buy a Sanden system, you receive the highest amount of Small-scale Technology Certificates (STCs) of any currently available hot water heat pump system. These STCs can be used to discount your purchase price. For more information, contact us.

Unlike other hot water heat pump systems, the Sanden Eco® system uses a smarter split system where the heat pump unit and stainless steel tank are installed separately. This allows easy on-site handling and installation, as well as options for the storage tank location, which can be up to 4 metres distance from the heat pump unit.

A heat pump is a device that uses a small amount of energy to move heat from one location to another, like an air conditioner in reverse.

It contains a fan that forces air through an evaporator that contains a refrigerant. The heat in the air passes through the evaporator and is absorbed by a natural refrigerant, R744 (CO2), which is ozone friendly and does not contribute to global warming.

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 sanden heat pump works

Heat Pump Unit

  • A high Coefficient of Performance (COP=4.5^) results in significantly reduced energy use and CO2
  • Up to 50% faster heat recovery than typical heat pumps. In ambient air of 20 ºC it takes approx 4 hours to heat 315 L of water from 17 ºC to 65 ºC.
  • Uses unique Ozone friendly R744 (CO2) refrigerant.
  • Simple installation by Plumber & Electrician, with no Refrigeration Mechanic required.
  • An automatic heating cycle, which makes it perfect for use with Off-Peak tariff.
  • Fitted with in-built freeze protection, making it suitable
for all climates (ie. -10 ºC to +43 ºC operating range).
  • No backup element required.
  • Whisper quiet operation, with industry leading noise
level of 38 dB – very neighbour friendly!
  • High quality, weather resistant construction
for outdoor location.
  • 3 year Warranty.


Stainless Steel Tank

  • Tank sizes offered – 250L
  • High quality, Australian made extra long life stainless steel cylinder.
  • Fully insulated for minimal heat loss.
  • Mains pressure rated.
  • 250 litre Tank with two installation options (tall with 
a reduced diameter or short with an increased diameter).
  • Safety pressure and temperature relief valve supplied.
  • 15 year Warranty.

Height 1800 mm
Hot Water Outlet & PTR Valve 1550 mm
Heat Pump Return15 1550 mm
Sensor Port82 825 mm
Cold Water Inlet / Heat Pump Flow 210 mm
Diameter 570 mm
Weight 60 kg approx.
Storage Capacity  250 L


Water Connections & Settings
Tank Relief Valve Setting (PTR Valve) 850 kPa
Expansion Control Valve Setting (ECV) 700 kPa
Maximum Mains Pressure Settings
With ECV 500 kPa
Inlet Water Operating Pressure 500 kPa
Adjustable Tempering Valve 1400 kPa max.

Technical Manual