Hot water heating, on average, makes up about a third of an average household’s energy bill. Costs vary depending on what technology you use to heat your water as well as how much you use.
Make a good investment
As well as upfront and running costs, consider these when you choose a new system.
- Renewable energy — Electricity in New Zealand is around 80-85% renewable, making an electric hot water system a low-emissions choice. Solar panels can be a great option for water heating to keep running costs down, and wood-fired wetbacks are also a sustainable option.
- Energy efficiency — A more efficient system is cheaper to run over time, so can be worth the upfront investment over less efficient options.
- The right size for you — The number of people in your house, the number of showers and baths, and whether your system feeds the dishwasher or washing machine will impact the required equipment size.
- Opportunities when building or renovating — Group together spaces that need hot water, (bathroom, kitchen, toilets and laundry). There’ll be less hot water left sitting in pipes, and it’ll reach your taps more quickly.
Compare home water heating options
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Electric water heaters and hot water heat pumps
Electric water heaters generally have lower running costs and lower emissions than gas water heaters. Hot water heat pumps are the most efficient option, requiring significantly less electricity to run than traditional electric water heater systems.
Hot water cylinders can be installed inside or outside the home. Rooftop solar can be used to power electric water heaters/hot water heat pump systems, further reducing running costs and emissions. -
Wood and wetbacks
Wetback systems circulate water from your hot water cylinder through pipes at the back of your firebox, using heat from your fire to warm the water.
Many wood or pellet fires, ranges or burner systems can have wetbacks fitted, making the most of a plentiful, renewable biofuel. -
Gas and LPG
Natural gas and bottled liquid petroleum gas (LPG) are fossil fuels, so directly generate greenhouse gas emissions. There are cylinder and continuous flow options – the most efficient is a condensing gas continuous flow system.
LPG is the most expensive option in terms of fuel costs. For gas water heating systems, there are fixed charges to consider for main gas supply, or bottle rental, as well as the energy costs.
Common questions
Thinking about solar?
There are two ways you can use solar energy to heat the water you use at home.
- Solar thermal systems produce heat rather than electricity. Solar thermal panels installed on your roof transfer heat from the sun to water stored in your hot water cylinder. Learn about thermal solar(external link)
- Photovoltaic solar panels (solar PV) convert energy from the sun into electricity which can be used to power an electric hot water system (including heat pump water heaters) as well as other electric appliances in the home.