Shower heading blasting hot water.
Research report
Last updated 7 April 2020

5 tips for saving money on your hot water

A few tweaks to your hot water system and usage can result in big savings.

If you’re in hot water over your latest power bill, remember water heating accounts for about 30% of household energy usage. A few tweaks to your hot water system and usage can result in big savings.

1. Insulate your cylinder

First, check your hot water system’s insulation. Cylinders and pipes installed before about 2002 generally aren’t well insulated – you can buy cylinder wraps from hardware stores for about $60 and pipe insulation from $5 per metre (ask for “thermal pipe lagging”). New cylinders lose less heat with extra insulation, but could still benefit from an insulating wrap.

2. Think about your electricity plan

You can also save money by running your hot water cylinder only at night, but you’ll need to be on one of the following electricity plans:

  • Controlled, where you have separately wired appliances (normally the hot water cylinder) that the electricity company can switch off for a few hours each day during peak times in return for a lower electricity price.
  • Time-of-use, where the amount you pay for all electricity changes depending on the time you use it, with lower night and off-peak tariffs.

Not sure which type of power plan you're on? Check your latest electricity bill, or contact your retailer to find out.

3. Install an efficient showerhead

Installing an efficient showerhead can save you hundreds of dollars per year. The rule of thumb is your shower is wasting water if it fills a 10L bucket in less than a minute. Replace your inefficient showerhead with one with a flow rate of less than 9L per minute. The showerhead will save water while still giving a good combination of comfort and effectiveness.

4. Try using both hot water cylinder elements

Some people think only using one hot water cylinder element can save power. But in fact, switching both elements on may be more efficient as it promotes even heating of the water through convection (the circulation of water due to hot water having a lower density and rising to the top).

5. Check the temperature

A hot water cylinder usually maintains its water temperature at about 60°C and 55°C at the tap (to prevent scalding). Anything above this mark is a waste of power and an injury risk. Check the temperatures at the tap first, if it's above 55°C it'll be a dead giveaway that it's set too high in the cylinder. Some cylinders will let you manually adjust the temperatures but you might need to call in a tradie to help out with this task.

Member comments

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Lindsay E.
07 Feb 2022
Check the temperature

A hot water cylinder has to heat the water stored inside it up above 60 degrees Celsius once a day. This is to kill the legionella bacteria that can breed in your water cylinder at lower temperatures. (like body temperature) Legionella is VERY dangerous. Most new installations will have a tempering valve fitted on the outlet of the hot water cylinder to reduce the water temperature going to the Bath, basin and shower to a maximum of 55 degrees. Getting the average householder to check their water temperature at the tap is okay, but there are more questions that need answered before they start adjusting their hot water cylinder thermostat.

Allan J.
21 Aug 2021

If you use your mixer tap in central position and not in the cold position when you open the tap, hot water will start filling the pipes and if you only run the tap for a short time you will not be aware as this hot water will not reach the tap but you will have wasted this hot water.

Previous member
26 Oct 2016
Clever NZ made Technology

I've installed one of the devices, one of the best decisions I made, we are a house hold of 4 Adults I can see how much hot water is in our cylinder - I can adjust the savings we want to make, We can see how much hot we are not using each day so we can increase or decrease our savings, We went away on labour weekend so just put our cylinder into holiday mode, knowing it's not heating unnecessarily. We heat our hot water from 12pm till 6pm so off peak- We have saved on average for the past two years $450 each year. It's NZ made and manufactured quite a clever piece of technology...Phillips Family Manukau Auckland

Darryl N.
10 Jun 2021
Which device is that?

Phillips family, I am intrigued by your comment but do not understand which device you are speaking of. Please reply with the name of the device you are talking about and any updates you might have with regard to its performance. Thanking you in advance.

22 Aug 2021

I think they are talking about Bobbie. Have a search on "Bobbie hot water saver"

Roland D.
25 Aug 2021
Clever NZ made Technology

Am I right in assuming that it needs to be installed between the hot water cylinder and the switch board. Therefore needing an electrician

Greg D.
05 Feb 2022
Are you sure?

Are you sure about these savings? Most hot water cylinders are controlled by your network distributor so take advantage of lower off-peak rates without this device. All it does is turn the element off at times but it then has to reheat the water later so any savings are lost. Better bet is to check the insulation to prevent heat loss.