Pool heating in New Zealand: heat pump, solar or gas

For most New Zealand home pools a heat pump is the practical choice: it costs more to buy than an electric element but much less to run, and it works on cool days. Solar is the cheapest to run but slow and weather-dependent, and gas heats fastest but costs the most to run. CheckMyBuilder prices installed pool heating at $4,000–15,000 (June 2026).

What does it cost to heat a pool in NZ?

Two costs: buying and installing the heater, then running it. CheckMyBuilder puts installation at $4,000–15,000, excluding GST, and notes that solar blankets are the cheap end of heating. On the running side, Calculate.co.nz's worked example of a heated pool spends $800 a year on heating out of about $2,275 in total running costs, making heating the biggest single line. That is one example's input, not a national average, but the shape holds: heat is where a heated pool's money goes.

How does a pool heat pump work?

A pool heat pump works like a heat pump in a house, in reverse of a fridge. It draws warmth out of the outside air and transfers it into the pool water as it passes through. Because it moves heat rather than generating it, each unit of electricity delivers several units of heat into the water. That is why heat pumps are the default recommendation for home pools that are used regularly.

• They work best in mild air. Efficiency drops as the air gets colder, so a heat pump in Central Otago in winter works far harder than one in Northland in March.
• They warm a pool steadily rather than quickly. Plan to leave it running through the season rather than switching it on the morning of a party.
• Sizing matters: an undersized unit never catches up on a cool week. The installer should size it to your pool's volume and how warm you want it. Our pool volume guide shows how to work that out.
• The outdoor unit makes some noise, so think about where it goes relative to your bedrooms and the neighbours.

Is solar pool heating worth it in New Zealand?

In the sunnier regions, for stretching summer into spring and autumn, it can be. Solar pool heating pumps the pool water through collectors on a sunny roof, where it picks up warmth and returns to the pool. After installation there's little to pay except the pump power. The catch is that it only heats when the sun is out, it heats slowly, and it needs a decent area of north-facing roof close to the pool.

Don't confuse solar pool heating with a solar blanket. A blanket is a floating cover that lets the sun warm the water and stops heat escaping at night. It's the cheapest heating there is, and it makes every other kind of heater work less.

When does gas pool heating make sense?

When you want heat quickly and use the pool occasionally. A gas heater burns natural gas or LPG to heat the water directly and brings a pool up to temperature faster than either alternative. It is usually the most expensive to run, though, and LPG means bottle deliveries. It's a common choice for spas and for pools heated only for weekends or events.

How do I keep pool heating costs down?

• Use a cover. Most of a pool's heat leaves through the surface, especially overnight. Calculate.co.nz's advice on its own running-cost calculator is that a cover is one of the main ways to cut costs, with heating the area where savings count most.
• Pick a sensible temperature. Every degree warmer costs more to hold, especially on cold nights.
• Shelter the pool from wind. Wind strips heat off the surface; fences, planting and screens help.
• Run the heat pump in the warmest part of the day if your power plan and routine allow.

Should I plan heating when I build the pool?

Yes. Pipework, a power supply to the heat pump, roof space for solar collectors, or a gas line are all cheaper to put in during the build than to retrofit. Even if you don't buy the heater straight away, ask your builder to leave provision for it. Our questions to ask a pool builder cover what to get in writing, and the pool cost calculator shows how heating changes the total.