Start with the job, then find the specialist
A single high-wall unit in a lounge, a ducted system in the ceiling space and a multi-room setup running several indoor units off one outdoor unit are different jobs, each with its own traps. Ask any installer how often they fit your type.
A ducted heat pump specialist will want to see the ceiling space before quoting, because BRANZ says ducts that are overlong, have many bends or run through uninsulated space can lose more than 30% of the heating energy. For a multi-room heat pump, Mitsubishi Electric NZ says long pipe runs and bends cut output, so the installer should be planning where the outdoor unit sits in relation to every room.
Placement trips up even simple jobs. In a BRANZ survey, more than a fifth of households said their heat pump wasn't installed in the right place, which BRANZ called a very poor outcome. Someone who fits heat pumps every week has seen enough lounges to know where the air needs to go.
Which registrations should a heat pump installer have?
Connecting a heat pump is prescribed electrical work, which only registered and licensed electrical workers can do or supervise. Some heat pump businesses employ their own electricians and others bring one in. Either is fine, as long as you know who's doing it and can find them on the EWRB register.
Refrigerant is the odd one out. There's no government licence for it here, only an industry arrangement about who can buy it. Our registration guide explains that arrangement and how to check each credential.
Gas heating is a separate trade. Installing, altering or repairing a gas appliance is gasfitting work regulated by the PGDB, and Tenancy Services says flued gas heating needs a registered gasfitter to install it. If you're weighing gas, see our gas heating page.
What the brand's warranty says about who installs it
Brands set their own rules, so read them before you choose. Rinnai NZ says installation must be done by a Rinnai accredited installer, and that claims may be invalid without that installer's details. Mitsubishi Electric NZ always recommends an Authorised Mitsubishi Electric Installer. Samsung NZ advises a professional technician authorised by Samsung. On its Weka Plus page, Gree NZ says that if your installer is industry qualified, that's okay with Gree.
Servicing counts too. Rinnai NZ says its systems should be maintained every year by a Rinnai authorised service centre, and Gree NZ's warranty card makes regular maintenance at intervals of no more than 12 months, by a qualified refrigeration and air conditioning tradesperson, a condition of the warranty. Ask whether the installer services what they fit.
And notice what a warranty leaves out. BDT, Mitsubishi Electric's NZ distributor, says its warranty covers the equipment only, not the installation or any heat load calculations. If a unit's undersized or badly placed, that's between you and whoever installed it.
Questions to ask before you say yes
- How many heat pumps like this one did you install last year?
- How did you work out the size, and what are its heating figures at 7 and 2 degrees?
- Who will do the electrical connection, and what's their name on the EWRB register?
- Where will the outdoor unit go, and how close is that to the neighbours' bedrooms?
- Are you accredited by this brand, and does the warranty depend on it?
- What corrosion protection would you use here, if we're near the sea or in a geothermal area?
- Is this a quote or an estimate?
- Do you service what you install, and how often does the brand want that done?
Unlicensed electrical work is never the shortcut
Every heat pump has to be wired in by a registered and licensed electrical worker. A January 2020 release for the Electrical Workers Registration Board described a heat pump business owner who wasn't licensed to do the electrical connection on an install, and the Registrar urged anyone having appliances installed to check the public register. Don't let anyone skip the electrician or the Certificate of Compliance to save time.
Signs to walk away
- They name a model before asking about the room, your insulation or how cold it gets.
- They can't tell you who will connect it.
- The outdoor unit goes wherever is quickest. Mitsubishi Electric NZ says units under houses and decks, or anywhere airflow is impeded, can create their own microclimate.
- Pressure to sign at the door. If they turned up uninvited, the uninvited direct sale rules let you cancel within 5 working days of getting your copy of the agreement.
- Claims they can't back up. Under the Fair Trading Act, a business needs reasonable grounds for what it says about its services at the time it says it.
- An offer to sort a Warmer Kiwi Homes grant for you. EECA decides eligibility, not the installer.
Your rights once the work's done
Under the Consumer Guarantees Act, the installer has to carry out the work with reasonable care and skill. The result must also be fit for any purpose you made known to them, such as keeping the lounge warm through a Canterbury winter, unless you didn't rely on their judgement. Those rights apply whatever the warranty says, and you can't sign them away.
If something's wrong and can be fixed, you can require them to fix it within a reasonable time. If they refuse or don't, you can have it fixed elsewhere and recover reasonable costs. The Disputes Tribunal hears claims up to $60,000 about whether a tradesperson did the work properly, even if you signed an agreement saying you wouldn't go there.
What you can check, and what they handle
You can
- Look up the electrical worker on the EWRB register.
- For gas work, look up the gasfitter on the PGDB register.
- Read the brand's warranty conditions before you choose a model.
- Note the rooms you actually heat, and when.
- Get the quote in writing, with the model number on it.
Leave to a licensed installer
- Sizing the heat pump to the room and your climate.
- Choosing an outdoor spot with the clearances BRANZ recommends.
- All refrigerant pipework and charging.
- The electrical connection, the Certificate of Compliance and the Electrical Safety Certificate.
- Corrosion protection where the site needs it.
What we'd do
If it were our home
We'd go with the installer who asks the most questions about the house, not the one who answers fastest. Before signing, we'd look up the electrical worker on the EWRB register and read the brand's warranty rules, because both are quick, and the warranty rules in particular can sink a claim later. Someone who fits your exact type every week, and services it afterwards, is worth waiting a few extra days for in winter.