Two in every three Kiwi homes now have a heat pump, so you’re in good company. Choosing one still takes a bit of thought. The right unit keeps the house warm for years on a modest power bill. The wrong one runs flat out on a frosty night, or blasts on and off in a room that’s too small for it, and you live with the noise and the power bill afterwards.
Seven steps, in the order that keeps you out of trouble. Get the first two right and the rest is mostly admin. None of it is complicated. It’s just easier in the right order than in the wrong one.
The short version:
- Get the size right for the room.
- Pick the type that suits your house.
- Check how it copes with frost, and how quiet it is.
- Compare brands on the energy label and the warranty.
- Choose a qualified installer.
- Get two or three quotes and compare them line by line.
- Check for grants, and the rental rules if you’re a landlord.
1. What size heat pump do I need?
Size is measured in kilowatts (kW) of heat, not the size of the box on the wall. It depends on the floor area, the ceiling height, your insulation, the windows, which way the room faces and where you live. A lounge in Whangārei and a lounge the same size in Invercargill need different units.
Bigger isn’t better. An oversized unit reaches the setting too quickly, then stops and starts all day, which wears it out and wastes power. Too small, and it runs flat out and still leaves the room cool on the coldest nights.
The gap between those two failures is narrower than most people expect, which is why a proper look at the room beats a guess from the floor plan.
What size heat pump do I need?
2. Which type of heat pump suits my house?
There are four main shapes, and the house often decides for you.
- High-wall. The most common choice. One indoor unit high on the wall heats one room or an open-plan space.
- Floor console. Sits low on the wall and heats from floor level. It suits a spot under a window, a low wall, or the space where an old fireplace or night store heater used to be.
- Ceiling cassette. Set into the ceiling, so only the grille shows.
- Ducted. One hidden indoor unit in the roof space or under the floor, with vents in each room. It needs plenty of ceiling or floor space, so it suits new builds and big renovations best.
If you want several rooms warm, you can also run a multi-room system: one outdoor unit feeding up to five indoor units, each with its own controls. All of them run in heating or cooling at the same time, not a mix.
Ducted takes more planning and more space than the rest, and it’s the one type worth sorting before the gib goes on.
Ducted vs high-wall heat pumpsSingle-room vs multi-roomFloor console heat pumps
Want the whole house warm, or comparing a heat pump with gas or a wood burner? Those questions are worth answering before you commit. A heat pump for hot water is a different product altogether, a cylinder rather than a room heater.
Central heating in NZHot water heat pumps
3. How does a heat pump cope with frost and noise?
Every heat pump gives less heat as the outdoor temperature drops, and it stops heating for short spells to clear ice off the outdoor unit. If your winter nights in Central Otago, Canterbury or the Central Plateau regularly fall below 7°C, check that the 2°C heating figure on the energy label isn’t much lower than the 7°C one. A unit that holds its output in the cold is worth paying for. One that only looks good on a mild day is a disappointment waiting for July. Some ranges are built for hard frosts and keep heating well below zero.
Noise matters most in bedrooms, and where the outdoor unit sits near a neighbour’s window. Showing noise on the label is optional in New Zealand, so you may need to look up the brochure figure. In a bedroom, listen to the indoor unit as well as the outdoor one.
Best heat pumps for frosty townsQuietest heat pumps in NZ
→ Related: Heat pump noise: what’s normal and what’s not
4. Which brand should I choose, and what does the warranty cover?
Every new heat pump carries the Zoned Energy Rating Label, and all of New Zealand sits in the Cold zone. More Cold zone stars means less power for the same heat, compared with other units of a similar size. The kWh per year figure gives a rough idea of how much power it will use. Read both, and compare models of similar capacity, or the stars tell you nothing useful.
Warranties differ by brand. Daikin’s is five years parts and labour on professionally installed home systems. General Airstage gives six years through one of its accredited installers and five years otherwise. Phone apps and wi-fi control vary from brand to brand as well, so check which one you’d be living with. The warranty and the app are the two bits you’ll actually live with, so they earn a minute of your attention.
Best heat pump brands in NZHow efficient are heat pumps?Smart and wi-fi heat pumps
5. Who is allowed to install a heat pump?
The electrical connection must be done by a licensed electrician, who gives you a Certificate of Compliance for the work. Ask to see their practising licence and check the expiry date. The refrigerant side is work for a trained refrigeration technician, since handling refrigerant gas needs its own certification. Most brands also expect an authorised or accredited installer before they’ll honour the warranty, so a cheap fit by someone outside the brand’s network can cost you later. Cheap installs are cheap for a reason, and the warranty is usually where it shows.
→ Related: How to choose a heat pump installer
6. How do I compare heat pump quotes?
Get two or three quotes from installers who come and look at the house. Ask each one to put the model number on the quote, so you can check the label figures and compare like with like: the same heating size, the same space covered, the same extras such as outdoor unit brackets and any electrical work. A cheaper quote is no bargain if the unit is smaller or the electrical work has been left off.
Under the Consumer Guarantees Act, the heat pump must be of acceptable quality and fit for its purpose, and the install must be done with due care and skill.
If you have solar panels, or you’re thinking about them, ask how the heat pump and the panels can work together.
How much does a heat pump cost?Heat pumps and solar
7. Can I get a grant, and what are the rental rules?
Some households can get help with the cost of a heat pump through the Warmer Kiwi Homes programme. Check whether you qualify before you sign a quote, because the rules decide who can do the install, and that can change which quote you accept.
Landlords have a legal floor to meet. The Healthy Homes heating standard requires a fixed heater of at least 1.5 kW that can heat the main living room, with a thermostat, and sized to the room’s required heating capacity. Above 2.4 kW, an electric heater won’t do, and a heat pump will.
Heat pump grants in NZHealthy Homes heating standard
How do I get heat pump quotes near me?
Once you know the size and type you’re after, the job can go to installers near you. Start from your town and compare the local businesses yourself, and get a couple of them out to look at the room.