Installers’ guide for hot water heat pumps

Publication date: October 2025

Hot water heat pumps are a great way to produce efficient, low-cost hot water in our homes. But how well they perform depends on choosing the right system for the home — and making sure it’s installed by a skilled, professional plumber who knows the ins and outs of the system.

To support good installations across New Zealand, EECA has worked with industry partners to produce a good practice guide for hot water heat pump installations.

By following this guide, installers can help to ensure that hot water heat pumps perform efficiently, reliably, and safely in New Zealand homes.

What the guide covers

The installers guide for hot water heat pumps includes:

  • how hot water heat pumps work
  • the impact of New Zealand’s varied climate
  • considerations for selecting the right size and system-type  
  • advice on refrigerant handling, pipework, plumbing and electrical works
  • guidance on homeowner maintenance and professional servicing. 

There is also an appendix of reference materials and relevant standards and regulations, making it a valuable resource for plumbers looking to keep up with new technologies, the latest best practices, and deliver great outcomes for customers.  

Heat pump water heater research

To encourage the uptake of HPWH technology in New Zealand EECA is undertaking research to understand:

  • more about the performance of these products
  • differences between products and product types
  • how the technology functions in different climate zones and households  
  • suitability for demand flexibility opportunities, given water can be heated off peak and stored for use.   

To gain these insights, EECA is installing and monitoring about 80 heat pump water heaters in a variety of New Zealand homes. 

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