Heat pumps
Heat pump electrical requirements in New Zealand
A fixed heat pump, often used as a reverse-cycle air conditioner in summer, needs more planning than choosing a wall and booking an installer. The electrical side depends on the exact unit, spare capacity in the existing installation, the cable route and the switchboard. A useful quote therefore starts with the model details and a look at the property, not a universal breaker or cable size.
Start with the actual heat pump
The manufacturer's instructions are the first electrical design input. They identify rated voltage, maximum input, recommended fuse or circuit protection, cable requirements and the wiring arrangement between the indoor and outdoor units. Two units that look similar on a brochure can ask different things of the electrical installation.
The installer selects and positions the equipment, plans the refrigerant pipework and condensate drainage, and confirms heating or cooling performance. A registered electrical worker deals with the fixed wiring, circuit protection, isolation, testing and applicable electrical documents. Coordinating both sides before mounting the units avoids a difficult cable route or a late switchboard surprise.
Does every heat pump need a dedicated circuit
Not necessarily for an existing home. EECA's Good Practice Guide for Heat Pump Installation says the supply may come from an existing circuit with sufficient spare capacity, or from a dedicated circuit, depending on the heat pump input and the existing electrical installation. For new buildings, the guide says a dedicated circuit should be used.
Both blanket answers can therefore be wrong. Reusing an overloaded or unsuitable circuit is not acceptable, but automatically pricing a new circuit before checking the unit and installation is not a complete assessment either. The electrician considers existing load, cable, protection and condition alongside the manufacturer's instructions.
If a dedicated circuit is required, the cable route can be straightforward through accessible roof or underfloor space, or more involved in a finished multi-level house. Route access is often a bigger cost factor than distance alone.
What the switchboard assessment covers
The switchboard check is not simply a search for an empty slot. The electrician considers available supply capacity, the demand already placed on it, the condition and labelling of the board, earthing, proposed circuit protection and whether there is a practical way to add the circuit.
An older switchboard does not automatically need replacement because a heat pump is being installed. Equally, a spare-looking position does not prove the installation has enough capacity. Some homes only need the new circuit and associated protection. Others need remedial work or a switchboard upgrade before the extra load can be connected safely.
A clear photo helps initial scoping, but it does not replace testing or an on-site assessment where the condition or capacity is uncertain. Leave every switchboard cover in place when taking the photo.
Isolation and the outdoor electrical connection
The EECA guide calls for a lockable isolating switch that is accessible for servicing and attached to the house, rather than mounted on the outdoor unit. This gives a service person a clear way to isolate the equipment without relying on an indoor controller.
Outdoor wiring needs protection suited to its location. The electrician plans how the cable enters the building, how it is supported and protected from weather or damage, and how the route coordinates with refrigerant pipes and drainage. A neat cover outside is not evidence that the wiring behind it is compliant, which is why testing before energisation matters.
Testing and electrical documents
New Zealand treats construction and alteration of fixed wiring as prescribed electrical work. It must be carried out by a person authorised for that work, then tested and certified according to its classification. For a typical new heat pump circuit, the paperwork commonly includes a Certificate of Compliance for fixed wiring and an Electrical Safety Certificate after connection. Limited maintenance work can have different documentation.
Keep the documents with the property records. They identify what work was done, who was responsible and which cited edition of the wiring standard was applied. UBL Electrical's approved service scope includes the electrical installation and connection of air conditioners and heat pumps. The business is run by Allen Zhu, a registered Electrical Engineer, EWRB practitioner EW155491.
Rental homes and the Healthy Homes heating standard
For a rental property, electrical capacity and Healthy Homes heating capacity are related but separate checks. Tenancy Services requires qualifying fixed heaters to directly heat the main living room and provide the required heating capacity. A heat pump can qualify, but installing any available unit does not by itself show that the heating standard has been met.
The heating assessment determines the output required for the room. The supplier selects equipment that meets that need. The electrician then checks whether the property's wiring and switchboard can support the selected unit and completes the fixed electrical work.
What to send when asking for a quote
Accurate details make the first electrical scope more useful. Send the heat pump model or supplier quote, a closed-cover switchboard photo, the proposed unit positions, any known cable route, the property type and age, and access details for a rental. UBL provides free quotes across metropolitan Auckland from an Albany base, with outer areas considered depending on the job. Call 021 0284 3210 or use the contact form.
- Heat pump make, model and specification sheet
- Clear switchboard photo with every cover left in place
- Proposed indoor and outdoor unit positions
- Known cable route through the roof, under the floor or along an exterior wall
- Property type, approximate age and known electrical alterations
- For a rental, the approval contact and access contact