How much does a heat pump cost to run in Auckland?

The short answer

A modern heat pump is the cheapest way to heat a New Zealand home. Running a 5 kW unit for a typical Auckland evening costs somewhere around 50c to $1.10 an hour depending on how hard it’s working — and far less once the room is up to temperature, because an inverter unit throttles back rather than switching on and off.

The reason is efficiency. A plug-in electric heater converts 1 kW of power into 1 kW of heat. A heat pump moves heat rather than creating it, so 1 kW of power delivers roughly 3 to 5 kW of heat. That ratio is the COP (Coefficient of Performance), and it’s why heat pumps cost a third to a fifth of what a fan heater costs to run.

What a unit of power costs in Auckland

MBIE’s quarterly survey puts the New Zealand average around 39–42 cents per kWh including GST as at 2026, with Auckland close to that average. Your own rate depends on your retailer and whether you’re on a low-user plan — check a recent bill, subtract the daily fixed charges, and divide what’s left by the kWh used.

The calculations below use 40c/kWh as a working figure.

Running cost by heat pump size

Heat pumps draw far less power than their heat output. A 5 kW unit doesn’t consume 5 kW — it consumes roughly 1.2–1.5 kW to produce that heat. These are realistic running figures at 40c/kWh:

• 2.5 kW unit (bedroom) — about 0.6–0.8 kW draw, roughly 25–30c per hour
• 3.5 kW unit (small living room) — about 0.9–1.1 kW draw, roughly 35–45c per hour
• 5.0 kW unit (standard living room) — about 1.2–1.5 kW draw, roughly 50–60c per hour
• 7.1 kW unit (large open-plan) — about 1.8–2.2 kW draw, roughly 70–90c per hour
• 9.5 kW unit (very large space) — about 2.5–3.0 kW draw, roughly $1.00–$1.20 per hour

Run a 5 kW unit four hours an evening through a 90-day Auckland winter and you’re looking at roughly $180–$220 for the season — for a warm, dry living room every night.

Why your actual cost will differ

Insulation and glazing

A well-insulated home with double glazing holds heat, so the unit spends most of its time ticking over on low. An uninsulated villa with single glazing bleeds heat continuously, and the unit works harder for longer. Insulation is the single biggest lever on running cost — bigger than the brand you choose.

Outdoor temperature

Heat pumps are rated at 7°C outdoor. As it gets colder they work harder and efficiency drops. Auckland’s mild winters are genuinely kind here — we rarely see the sub-zero conditions where efficiency falls away sharply.

Sizing

This is the one people get wrong. An undersized unit runs flat out permanently and never quite gets there — it costs more to run, not less. An oversized unit short-cycles instead of settling into efficient low-speed operation. Getting the size right is a running-cost decision as much as a comfort one. Our sizing calculator gives you a starting point.

How you use it

Set it and leave it around 19–21°C rather than cranking it to 28°C to “heat up faster” — it doesn’t work that way, and it wastes power. Running steadily at a moderate temperature is cheaper than blasting and switching off.

Cutting your running costs

• Clean the filters every couple of months. Clogged filters choke airflow and force the unit to work harder for the same heat. This is free and it’s the most effective thing you can do.
• Get it serviced annually. A dirty coil or low charge quietly costs you money every hour it runs. Servicing pays for itself.
• Close curtains at dusk. Glass is where most of the heat escapes.
• Use the timer. Warming the room before you get home beats blasting it when you arrive.
• Check your power plan. Rates vary by several cents per kWh between retailers — that’s a real percentage off every hour you run.

How it compares

At 40c/kWh, running each of these for one hour:

• Heat pump (5 kW output) — roughly 50–60c
• Plug-in electric heater (2 kW) — about 80c, for less than half the heat
• Oil column heater (2.4 kW) — about 96c, for half the heat

That’s the whole argument. A heat pump delivers two to three times the heat for less money, and it dehumidifies while it does it — which in an Auckland winter matters as much as the warmth.