10 Jun 2024

To turn your heatpump off or not?

2:13 pm on 10 June 2024

By Anabela Rea of Stuff

Heat Pump

Heat Pump Photo: 123RF

The introduction of heat pumps has irrefutably changed our winter lives.

Down here in little old New Zealand, where double-glazing is still a luxury worth highlighting when you sell a house, and insulation standards have to be mandated, winter used to be a very dreary time indeed.

These days, it's somewhat irresistible to lounge beneath a tropical, ever-present 23 or so degrees. (As I write this story, I am in fact, indulging in this activity.)

Some heat pump installers recommend leaving your heat pump on 24/7, the theory being that once your home reaches the set temperature, it will take less energy to maintain it there.

But then the bill arrives.

So, to turn your heat pump off or not? That is the golden question...

Jessica Walker, spokesperson for Consumer NZ, says this topic is "a really controversial one" but following their recommended advice could save you $320 a year in power bills.

According to product research conducted by Consumer NZ last year, you should turn your heat pump on and off as needed.

"You should only ever have your heat pump running if you're at home. Heat pumps work rapidly once you turn them on, so don't bother leaving them on when you're not there," says James le Page, product test team leader, writing in a Consumer NZ guide.

"They work so fast getting the room up to temperature that they don't use that much power starting from scratch."

However, this does come with a caveat - if your home is very well insulated, you may be able to leave it on.

"For the few people who have a house that is super airtight - so with no gaps around doors and windows, insulation above building code requirements, double glazing, thermal drapes and a ventilation system - they might be able to leave their heat pump on all day every day," recommends le Page.

Even Genesis Energy seems to be on the same page. In a blog piece informing customers how to use the heat pump most efficiently, Genesis recommends the following:

"During the colder months in New Zealand, it's recommended to set your heat pump to around 18 to 22 degrees. While this might seem low for making your home extra toasty in the winter, setting the unit to very high temperatures will consume much more energy and put unnecessary load on your heat pump.

"If it's cold enough that you want to run the heating all night, reduce the temperature down to around 16-18 degrees, this will ensure you'll wake up cosy and your use of the heat pump will still be really cost efficient."

Walker says that overall, their top tips at Consumer NZ are to only turn on your heat pump when you need it, and to never have it set upwards of 21 degrees


"If you're finding that's not warm enough, then you need to turn your fan up, rather than turn the temperature up," she says.

"But the key here, and I didn't know this myself until I joined Consumer, is to make sure that your filters are vacuumed, because that makes such a difference."

Making sure your filters are vacuumed will bring your bills down as well, says Walker.

"Because the whole unit isn't having to work so hard to pump out warm air."

"We put a figure on it last year actually, how much you could save by running your heat pump efficiently. So we think that if you set your heat pump to a maximum of 21 degrees, it could save you about $320 a year."

Top tips for making the most of your heat pump:

  • Don't leave your heat pump on all the time, unless your house is very well insulated. That includes the windows.
  • Program your heat pump to turn on before you come home from work.
  • If you come home and it's really cold, crank up the fan level to heat the room quickly.
  • Make sure the heat pump's filters are cleaned regularly to allow air to flow fast.
  • Don't set your heat pump to above 21 degrees.
  • Utilise window coverings, like blinds and curtains, to prevent thermal loss.
  • Keep your home cosy by blocking draughts under doors with a 'draught snake' or even just an old towel.

- This story was first published by Stuff

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