hot water | 17th Aug, 2016

Saving water at home - showers, baths, dishwashers

Whether you're taking a shower or bath, washing dishes by hand or using a dishwasher, what are some ways to save water?

Efficient hand-dishwashing techniques:

  • Don’t wash or rinse under a running tap; put the plug in the sink first!
  • Fill the sink according to the number of dishes you need to wash – only part fill for a few dishes OR wait until you have enough dishes for a full sink load. (You’ll use more energy with several small washes than one big one.)
  • Use cold or warm water instead of hot.
  • Use washing-up liquid sparingly as this will reduce the amount of rinsing required (the dissolved dishwashing liquid you can’t see does the work, not the bubbles you can see).
  • Use a second, smaller sink or bowl for rinsing.

Using your dishwasher efficiently:

  • Only run the dishwasher when you have a full load.
  • Choose an eco-friendly dishwasher – at least 3.5 star energy and 3.5 star water ratings.
  • Select the economy option whenever possible.
  • Scrape food into the compost or use the rinse-hold setting on the dishwasher, if it has one, rather than rinsing dishes under the tap.
  • Keep the filters clean.
  • If you have a time-of-use (or peak and off-peak) electricity tariff, use the delay start option to run the dishwasher during off-peak periods.
  • Select a machine with half-wash and economy (or eco) options if you are a small household, as running a dishwasher when only partly full wastes energy.
  • Select a machine with dual hot and cold water connections, since hot water will be heated at a lower cost using the hot water heater in your home, than if the dishwasher heats it.
  • Hand wash big pots (space hogs), knives (get dull from clanking against dishes), and plastic containers (release harmful chemicals when washed).


  • Take shorter showers. Limit time spent in the shower to soap up, wash down, and rinse off. Shorter showers save on energy costs associated with heating water. What are some other (less expensive) ways you could use, to help you wake up, or to have some time to yourself?
  • Use a shower timer.
  • Shave your legs before taking a shower. Use running shower water to rinse off.
  • Replace your old shower head with a water saving-saving showerhead. You can save $200-$800 dollars a year, and 8-16 L/minute of water.
  • Consider an instantaneous water heater if your existing water heater is located some distance to the bathroom. Talk to a plumber first to make sure it will work adequately with your 3-star showerhead.


  • Only fill the tub with as much water as needed. Use less for children.
  • Consider using the bath water for more than one person, or for other uses like your washing machine or watering your garden.
  • Check the temperature as you fill. Adding extra water to get the correct temperature after the bath is at the right level is wasteful.
  • Regularly check your plug for leaks and replace as necessary.

General tips for saving hot water:

  • Insulate hot water pipes. This avoids wasting water while waiting for hot water to flow through, and therefore saves energy.
  • Make sure your hot water system thermostat is not set too high. Adding cold water to cool very hot water is wasteful. 50 C for small hot water tanks (instantaneous hot water) and 60 C for large hot water tanks. You can test the temperature of your hot water by holding a thermometer under your tap and turning on only the hot water tap, then waiting until the red line stops moving.
  • New hot water systems allow you to specify the temperature without adding cold water.
  • Install water efficient tapware or retrofit old tapware with aerators or flow control valves, available from hardware stores.

Further resources:

Your Energy Savings – UseWater Efficiently – Reducing Water Demand

Sustainability Victoria – How to Reduce Hot Water Running Costs