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Technical & Install - Domestic
Hot Water Systems

The Calitec System is a refrigerant cycle split system. This means the outdoor unit pumps its refrigerant through a coil inside the hot water cylinder, where the heat is released and the water heated. The 20 metre pipe length between the outdoor unit and hot water cylinder gives you plenty of flexibility to place the outdoor unit out of sight.

Calitec Hot Water System Diagram 2023 Heat pump water heating

The Calitec System is an intelligently controlled set and forget system. It provides a reliable hot water supply in any weather and any time of the day, saving you up to 70% of your hot water costs. As an average shower costs about $1, you can save up to 70 cents with every shower.

The 4 kW heating capacity is more than a standard electric heater (2 to 2.4 kW), ensuring a much faster recovery time for your hot water cylinder (as well as using less power). Our high quality stainless steel hot water cylinders are fully insulated with Polyurethane Foam.

The Calitec System is designed and built using the highest quality parts, and is designed to last at least 10-15 years. After this time, your outdoor unit may need replacing but there is no need to replace the whole system. 

There is a 5 year warranty on the outdoor unit and 20 year warranty on the hot water cylinder.

For full warranty details click here. These units are tested with New Zealand and international certificates.


Specifications - Outdoor Heat Pump Unit 250L/300L

Anchor specification table
specifications Calitec heat pump hot water system - outdoor unit

Some recent upgrades in our models

In 2020 we upgraded our systems. The most important upgrades are the inner cylinder, which is made of Duplex (2205) stainless steel, and the double layer evaporator in the outdoor unit. Using Duplex stainless steel for the inner cylinder ensures it is resistant against impurities in your water.

Other upgrades on the hot water system are:

  • a better insulation layer

  • improved back-up heater

  • the multiple cold and hot water connection options

  • double-layer evaporator from the outdoor unit ensuring a better efficiency at lower ambient temperatures

  • The case is now made out of 1mm 304 stainless steel

  • The controller has a backlight for easier reading​

Installation and maintenance

The installation of a Calitec Hot Water System is only allowed by qualified tradesmen. It must be installed according to New Zealand building codes and local regulations.

It is important you do not install the unit by yourself, unless you are a suitably qualified. Installation by an unqualified person could result in injury, due to fire or electric shock, and incorrect installation can also void the warranty. 


The good news is that Calitec hot water systems are a set-and-forget system with very little maintenance. Once your installer(s) are finished there is very little you have to do.

Where to place the outdoor unit

We recommend placing your outdoor unit in a location where: 

  • It is not exposed to strong winds. 

  • Airflow is good and dustless. At least 100mm space around the unit and 800mm space at the front.  

  • Neighbours are not annoyed by the operating sound. 

  • There is no risk of combustible gas leakage.  

  • The condensation water can flow to a drain or can be absorbed into the soil. 

  • Flooding water cannot reach the base of the unit. 

  • The outdoor unit should stand on feet on a level base or fitted with a wall bracket. 

Please avoid locations where the following could occur: 

  • Flammable gas leaks

  • Exposure to a lot of machine oil 

  • Exposure to sulphide gas 


Maintenance of outdoor unit

It is very important that the air can flow unhampered through the outside unit. Keep it free from weeds and spider webs and don’t block it off in any other way. A restricted or blocked airflow can result in higher power consumption or failure of the unit.

It is also very important that the compressor unit is fitted level to the ground. Your installer will make sure that it is fitted correctly, but check regularly to make sure that it remains level. The lifetime of the compressor unit will be shortened if it is operating on uneven ground, so please inform your installer if the level of your unit needs correcting.


Hot water cylinder installation

The hot water cylinder can be used as a low water pressure cylinder or as a mains water pressure cylinder and can be placed either in or outside. If you install the hot water cylinder outside, make sure that you insulate the water pipes to avoid heat loss.

The installation must be carried out by a qualified plumber and installed vertically, and according to local rules and regulations. The hot water cylinder is just like a normal hot water cylinder, with different heating.

The electric heater must be connected by a qualified electrician. The electric heater is strictly a back-up heater and should be switched off with normal operation of the heat pump hot water system. 

Hot water cylinder maintenance

Mains pressure systems are fitted with a Pressure & Temperature Relief Valve (PTR Valve) and once a month the release mechanism on the valve has to be activated to ensure it continues to function correctly. When the release mechanism is jammed, the hot water pressure in your system could become too high, causing issues.

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