Saving money on water


A day in the life


Water heated by a boiler

In most homes, the hot water is supplied by the main central heating boiler, either directly if it is a combi boiler, or from a hot water cylinder. Often there will be an electric immersion heater in the cylinder as well.

Tip – use the boiler to heat the water, even in the summer. The immersion heater will be more expensive, and should only be used as an emergency back-up.

Find out more about controls that will let you run your boiler more efficiently.


Water heated by immersion

In some homes, particularly those with electric storage heaters, the water can only be heated by immersion heater. There may be two immersions, one in the top of the cylinder and one in the bottom. Usually the bottom heater comes on at night, and heats the whole cylinder using cheap off-peak electricity. The top heater is used to provide additional hot water during the day if required, using expensive peak rate electricity.

Tip – DO NOT leave a peak rate immersion heater on all day and all night. You will waste a lot of money keeping water hot when you don’t need it.

Find out about using controls for your system that will use less energy and save you money.


Five steps to saving money on your hot water bills

  1. Use less – get more information and advice on using less water, and less hot water in particular.
  2. Insulate your hot water cylinder – a well fitted tank jacket could save you around £20 to £30 a year, more if you heat your water electrically. Insulating the hot water pipes will save more energy, and can help your taps to run hot more quickly.  Find out more about tank and pipe insulation.
  3. Control – make sure you have the right controls, and have them set correctly to give you enough hot water when you want it, and not when you don’t. Find out more about boiler controls, and  controls for immersion heaters.
  4. Fuel switching – gas is cheaper than electricity or oil, so consider switching if you can. Find out about improving or switching an electric system.
  5. Solar – once fitted, solar water heating could provide a good proportion of your hot water requirements with virtually no running costs. 

Passive Flue Gas Heat Recovery Device (PFGHRD)

If you have a combi boiler, you may not be able to fit solar water heating, but you may be able to fit a Passive Flue Gas Heat Recovery Device (PFGHRD). This recovers additional heat from the boiler’s flue gases and uses it specifically to heat the hot water supply.