Heat Pump Hot Water Installation Auckland

What is a heat pump hot water cylinder?

A heat pump hot water cylinder is a form of hot water storage tank used in combination with a heat pump system. The cylinder is normally constructed of stainless steel and is insulated to maintain the temperature of the hot water.

In order to heat the water held in the cylinder, the heat pump system extracts heat from the surrounding air or ground. Pipes and valves are then used to distribute the hot water around the house.

The system’s storage component, the heat pump hot water cylinder, ensures that the heat pump runs effectively and consistently supplies the residence with hot water.

Heat pump water heaters use a similar technology to heat up water as heat pumps do to heat rooms. They use electrical energy and a refrigerant to extract energy from outdoor heat to heat the room, the water is then stored in an insulated hot water tank.

Heat pump water heaters are becoming more popular in New Zealand because they give an alternate way to heat your water. At the moment, popular systems include gas and electric hot water cylinders, as well as gas continuous flow systems. Heat pump water heaters operate similarly to heat pumps that heat your home, extracting heat from the outside air to heat your water.

There are two sorts of systems: those in which the heat pump is integrated into the hot water cylinder and those in which the system is divided. The heat pump unit is outdoors, while the hot water cylinder is inside your home.

Heat Pump Hot Water

How does a heat pump hot water cylinder work?

Heat pump hot water cylinders work in a similar way to refrigerators, however instead of pulling heat from inside a box and sending it into the surrounding room they pull the heat from the surrounding room and send it into a hot water cylinder to heat the water.

The hot water is then held in the insulated cylinder before being supplied to the property through pipes and valves. A thermostat controls the temperature of the water and allows you to set the desired temperature in the heat pump hot water cylinder.

When the hot water is utilised, the cold water returns to the bottom of the cylinder and is heated once again by the heat pump system. This procedure is repeated until the required water temperature is achieved and maintained.

In general, a heat pump hot water cylinder works by absorbing heat from the outside air or ground and transferring it to the water contained in the cylinder, therefore delivering a consistent supply of hot water.

Advantages of a Heat Pump Hot Water Cylinder

Energy efficient

  • The heat pump’s hot water cylinder transfers heat to the cylinder’s water. This method can provide hot water at a fraction of the cost of resistive heating.
  • They can be up to three times more energy efficient than conventional electric resistance hot water cylinders. 

Low costs

  • A well designed and installed system will use a lot less energy than standard electric cylinders.
  • This system suits a household that has moderate to high hot water needs and has relatively low running costs; however, it expensive to install and upfront costs are high.


  • The system can be modified to heat water for a hot tub, spa or swimming pool more efficiently than an electric heater.
  • You are able to retrofit a heat pump system to work with an existing conventional hot water storage cylinder.

It is also important to keep in mind that the warmer the temperature of the outside air is, the more efficiently the heat pump hot heater cylinder runs. Not all heat pumps will run in colder temperatures and the system may revert to an electric element as a backup, which means they are not suitable for all geographic locations in New Zealand.

You will also need to ensure you live in the right environment, in geothermal or coastal areas the system requires suitable protection against corrosion. As with other tank-based systems, heat pump water heaters need to be installed correctly to ensure the water temperature is maintained at 60°C to prevent the growth of legionella bacteria.

There is a range of different heat pump water systems to choose from – contact one of our heating specialists today to discuss which heating system is right for you.

Standalone Heat Pump Hot Water Cylinder

You are able to purchase a stand alone heat pump water heater system as an integrated unit with a built in hot water storage tank and back up resistance heating elements. 

Split System Heat Pump Hot Water Cylinder

Split systems have the compressor unit outside and the hot water tank generally inside although the tank can also be located outside the house separate from the compressor. In some cases you can retro-fit and use your existing hot water tank. 
Heat Pump Hot Water CylinderThis will require the installation to be in locations that remain in the 4.4C – 32.2 C temperature range year round and you must provide at least 28.3 cubic meters of air space around the water heater.

Recommended Heat Pump Hot Water brands for you to use: 

  • Ecospring water heater
  • Steibel Eltron water heater
  • Rheem water heater
  • Aquafire water heater
  • Rinnai water heater

Frequently Asked Questions

A good heat pump hot water system depends on several factors. Generally, the best heat pump hot water system uses modern technology and has a high coefficient of performance (COP), which means it can create more heat energy than it consumes in electrical energy. The system should also have a solid guarantee, be energy efficient, and be quiet.

The size of the heat pump also plays an important role. If there are multiple showers in a house or there are a lot people living the heat pump should hold a large volume of hot water (at least 180 litres) so that everyone in the house can get an even supply of high pressured, hot water. 

We recommend getting in touch with our team to advise you on the best heat pump hot water systems for your home.