How to reduce your hot water costs
After heating the home, hot water is often the next biggest energy use. Here are the practical ways to trim it.
Heating water uses a surprising amount of energy. These changes cut the cost without leaving you taking cold showers.
Quick, free changes
- Take slightly shorter showers — a minute or two off each one adds up.
- Choose showers over baths (a bath typically uses far more hot water).
- Only run the dishwasher and washing machine when full.
- Wash clothes at 30°C — modern detergents work fine and you heat far less water.
- Fix dripping hot taps promptly.
Cheap upgrades
- Fit a water-efficient or aerated showerhead.
- Insulate your hot water pipes with foam lagging.
- Fit a hot water cylinder jacket if you have a tank.
- Lower the cylinder thermostat to around 60°C — hot enough for safety, not scalding or wasteful.
- Put the immersion heater on a timer.
If you have a cylinder
Set the immersion/cylinder thermostat to around 60°C — high enough to keep the water safe from bacteria, but not so high you're wasting energy or risking scalds. Heating it on a timer for when you need it, rather than constantly, saves more.
The big picture
If you're replacing your heating system anyway, how you heat water (combi on demand vs stored cylinder) affects efficiency — worth factoring in when the time comes.
Match the system to your use
How you heat water matters. A combi boiler heats it on demand with nothing stored, which suits smaller households. A cylinder stores hot water, which suits homes with higher simultaneous demand but loses a little heat in standby — minimised with a good cylinder jacket and pipe lagging. If you're replacing your heating, it's worth thinking about which suits your household.
The quick wins again
- Shorter showers, and showers over baths.
- Wash clothes at 30°C.
- Lag pipes, jacket the cylinder, fix dripping hot taps.
More practical advice in our Insights & Guides.