Electric hot water cylinders

Electric hot water cylinders are the most common form of water heating in New Zealand.


  • Cheapest upfront cost among the water heating options.

  • You can buy cylinders with additional connections suitable for having a solar water heater, heat pump water heater or wetback added in the future.

  • You may be able to switch to a night rate electricity tariff, which could halve your hot water bill. It's not available in all areas of the country though - check with your electricity supplier first. Before switching to night rate, test that your cylinder is big enough to store a day's water. Switch it off first thing in the morning and back on before you go to bed for a couple of days to see if you run out of hot water. If you have enough hot water to see you through, organise a night rate tariff with your electricity supplier. For those with insufficient hot water, some electricity providers offer a night rate tariff with a morning hot water boost. Check with your provider to see if they offer this service.

Keep in mind

  • The running costs of electric hot water cylinders are relatively expensive compared to other water heating options (unless a cheaper night rate tariff is used).

  • Older hot water cylinders installed pre-2002 should have a special hot water cylinder wrap put on them and the first metre of their piping, to prevent heat loss.

  • Use our water heating systems tool to compare the upfront and ongoing costs of different water heating options for your situation.

 Water heating systems tool

How they work

Electric hot water cylinders use an electric element in an insulated tank to heat the water to a temperature set by a thermostat.