- Connection
- Hard-wired Not a plug-in appliance
- Circuit
- Usually dedicated Larger units commonly require one
- Outdoor unit
- Isolator A switch beside it, so it can be made safe
- Paperwork
- CoC Electrical Certificate of Compliance
Most heat pump quotes bundle the electrical work into one line, which makes it hard to tell whether two quotes include the same thing. This guide explains what the electrical side of a heat pump install involves, so you can read that line properly and spot when your house needs more than the standard job.
Does a heat pump need its own circuit?
Usually, yes. Manufacturers' installation manuals for split systems generally specify a dedicated circuit with its own protection device, sized for the unit, and larger living-area and ducted units commonly need one. A small bedroom unit can sometimes share a circuit, but that's the electrician's call based on the model's rated current and what else is on the circuit, not something to assume to save money. If the quote doesn't say, ask: "Is this a new dedicated circuit from the switchboard?"
Can I plug a heat pump into a normal power point?
Not a split-system heat pump. The outdoor unit is wired in permanently, and the indoor unit takes its power and control signal from the outdoor unit through the interconnecting cable. Plug-in portable air conditioners exist, but they're a different appliance: a single box with a hose out the window, much less efficient, and not what anyone in New Zealand means by a heat pump.
Why is there a switch next to the outdoor unit?
It's the isolator. The wiring rules (AS/NZS 3000) call for a way to cut the power at the outdoor unit, so a technician servicing it can make it safe without walking back to the switchboard. It should be weatherproof, within reach of the unit and clearly labelled. It's also the switch you'll use when you clean the filters properly.
Will my switchboard need upgrading for a heat pump?
Only if it can't take another circuit safely. The electrician looks for three things: a spare way (physical space) for the new protection device, RCD protection, and enough capacity on the supply for the heat pump on a cold night alongside everything else. Older boards with ceramic rewireable fuses and no RCDs are the common problem in pre-1980s homes, and switchboard work is priced separately from the heat pump. A good quote names it as a line item rather than leaving it to install day.
| Item | Standard install? | Notes |
|---|---|---|
| New circuit and protection device in the switchboard | Usually included | Ask if it's a dedicated circuit |
| Cable from the switchboard to the outdoor unit | Included up to a set length | Longer runs, or runs through finished walls, cost more |
| Weatherproof isolator beside the outdoor unit | Included | Required so the unit can be made safe |
| Interconnecting cable, outdoor to indoor unit | Included | Usually runs with the refrigerant pipes |
| Testing and Certificate of Compliance | Included | You should receive the CoC |
| Switchboard upgrade or replacement | Extra | Old fuses, no space, or no RCDs |
Electrical work must be done by a person registered with the Electrical Workers Registration Board.
Who is allowed to wire a heat pump in?
A registered electrical worker. Connecting a heat pump to fixed wiring is prescribed electrical work, and you can check any electrician's registration on the EWRB's public register. The refrigerant side is a separate trade skill: it has to be done by someone trained and certified to handle refrigerant gases. Many heat pump companies have both in-house; others subcontract the electrical connection. Either is fine, as long as the quote says who does what.
What paperwork should I get?
An electrical Certificate of Compliance for the connection, plus the model and serial numbers and the installer's invoice. Keep all three together. Manufacturers usually ask for proof of a professional install for a warranty claim, and a buyer's building inspector may ask about it when you sell. More on the whole job in our installation process guide.
Frequently asked questions
Does a heat pump need a dedicated circuit in NZ?
Usually. Manufacturers generally specify one, and larger units commonly require it. The registered electrician decides based on the model's rated current and what else is on the circuit.
Can a heat pump be plugged into a wall socket?
Not a split-system heat pump. It is hard-wired by a registered electrician. Plug-in portable air conditioners are a different, less efficient appliance.
Is an isolation switch required for a heat pump?
Yes. The wiring rules call for an isolator at the outdoor unit so it can be made safe for servicing. It should be weatherproof and labelled.
Do I need an electrician to install a heat pump?
Yes, for the electrical connection. It's prescribed electrical work for a registered electrical worker, who should give you a Certificate of Compliance.
Will a heat pump overload my switchboard?
Not if it's sized and wired properly. The electrician checks spare space, RCD protection and supply capacity before adding the circuit, and quotes any switchboard work separately.
How much does the electrical work for a heat pump cost?
It's normally included in a standard installed price. Extras are long cable runs, runs through finished walls, and switchboard upgrades, which should be itemised in your quote.