Hot water heat pump cost in NZ: price to buy, install and run
A hot water heat pump is the single biggest efficiency upgrade most New Zealand homes can make, because water heating is 25-30% of the average power bill. But it is also a several-thousand-dollar purchase, so the first question everyone asks is the right one: what does it actually cost? There are two numbers that matter - the price to buy and install it, and the price to run it - and this guide covers both.
What a hot water heat pump costs to buy (2026)
In New Zealand, expect to pay somewhere between $6,000 and $9,000 installed, depending on the type of unit and how tricky your install is. EECA puts a typical job near $7,000, and Consumer NZ reported a real-world install at $8,505. The appliance on its own is usually $4,500-$6,500; the balance is the plumber and electrician - on most jobs, labour is more than the box. Here is the rough lie of the land:
| Type | Typical size | Installed price |
|---|---|---|
| Integrated (all-in-one) | 170-200 L | $6,000-$7,500 |
| Integrated (all-in-one) | 250-300 L | $6,500-$8,500 |
| Split system (tank in, compressor out) | 200-300 L | $7,500-$9,500 |
| Standard electric cylinder (for comparison) | 180-300 L | $2,000-$4,000 |
Relocating the cylinder, extra pipework or an outdoor split install can push a job to $9,000-$13,000. If your old cylinder sits where the new unit can go, a straight swap is the cheapest path.
An integrated unit puts the tank and the compressor in one cabinet - simplest to install, but the whole thing hums, so it wants a garage, laundry or outdoor spot with airflow. A split system keeps the compressor outside and the tank inside, so it is quieter indoors and more flexible on siting, but costs more to buy and plumb.
What drives the install price
The spread above is mostly about installation, not the box. The things that push you toward the top of the range:
- Relocating the tank: if the new unit will not fit where the old cylinder sat, you are paying for new pipework and often new wiring.
- Split vs integrated: a split system needs refrigerant lines run between the indoor tank and the outdoor compressor - more labour.
- Electrical work: some installs need a dedicated circuit or a controlled/night-rate connection added.
- Condensate and siting: the unit produces condensate that has to drain somewhere, and it needs a spot with enough air volume - a sealed cupboard usually will not do for an integrated unit.
The cheapest install is a like-for-like swap where an integrated unit drops straight into the old cylinder's position with existing pipework and power. If you are building or renovating, designing the spot in from the start saves the most.
What it costs to run - and saves
This is where the money comes back. A standard electric cylinder turns one unit of electricity into one unit of heat. A hot water heat pump works like a fridge in reverse, pulling warmth from the air, so it delivers the same hot water using 60-75% less electricity (a coefficient of performance, or COP, of roughly 3-4).
In real-world NZ conditions, EECA estimates a hot water heat pump saves a typical household around $300-$700 a year versus a standard electric cylinder - its own worked example, a 3-person Auckland home on average hot-water use, comes out near $284 a year. Larger households, heavier hot-water use and dearer regional rates all push the saving toward the top of that range. The theoretical best case at a steady COP of 3 is higher again; we work through that modelled calculation in the companion piece, hot water heat pump vs electric cylinder running cost, but real installs rarely hit it because winter COP is lower and many cylinders already heat overnight on a cheap night rate.
Payback: is it worth it?
Put the two numbers together. You spend roughly $3,000-$5,000 extra upfront over a replacement cylinder, and save $300-$700 a year. On the full price that is a payback of around 7-12 years - Consumer NZ puts it "within 10 years" - after which it is money in your pocket for the rest of the unit's ~15-year life.
The economics are best when your old cylinder has just died. You were going to spend the cylinder money anyway, so only the $3,000-$5,000 gap is the real investment, which pays back far sooner - often in five to nine years, quicker still for a high hot-water household on an expensive rate. They are weakest if your current cylinder is only a few years old and working fine, because then the whole purchase price is the investment.
Which size for your household?
- 1-2 people: a 170-200 L integrated unit is usually plenty.
- 3-4 people: 250-300 L, so you are not running out mid-morning.
- 5+ people, or a big-shower household: 300 L, and think about recovery rate as well as tank size.
Bigger is not automatically better - an oversized tank has more standing heat loss - so match the size to how much hot water you actually draw. Also weigh the cold-weather catch: a heat pump's efficiency drops as the air gets colder, so in Invercargill or Dunedin a unit works harder in winter than the same one in Auckland. It still wins over the year everywhere in NZ, just by a slightly smaller margin down south.
Work out your own number
Your real saving depends on your region's rate and how much hot water your household uses. Plug both into the NZ Power Bill Calculator to see the cylinder-versus-heat-pump gap for your own home, then weigh it against the install price above.
Related guides
- Hot water heat pump vs electric cylinder - the full year-by-year running-cost maths
- Hot water heat pump running cost - the live per-region figure
- Electric hot water cylinder running cost - what you are upgrading from
- The most expensive appliances in NZ homes - where hot water ranks