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Storage heaters

The principle of a storage heater is that it contains ceramic bricks capable of storing large amounts of heat. These are heated overnight using off-peak lower cost electricity on Economy 7 or Economy 10 tariffs. The stored heat is then gradually released the following day.


  • Storage heating systems consist primarily of individual storage heaters, typically they rely on a separate wiring system within the home for cheaper off-peak (Economy 7 or Economy 10) electricity, so can still be described as a ‘centralised’ system. The same wiring may also be used to heat a hot water cistern (tank).
  • Example of power used by a storage heater in a room that requires 1kW of heat.
    –  Requires a storage heater that consumes around 3.2 kW per hour.
    –  Economy 7 tariff = 7 hours electricity at a cheaper rate during the night.
    –  Storage heater consumes 3.2kW per hour for 7 hours = 22.4kW per night (around £3.15 per night).
    –  Releases 22.4kW of heat consumed over a 24 hour period = heat output of 0.933kW of heat per hour.

This means that storage heaters are efficient, in that they give out all the energy that they consume, however they consume a lot of energy and as such are very expensive to run.

Typical storage heater


  • Electric night storage heaters are much cheaper to install than gas central heating systems as they don’t require pipe-work or a flue.
  • With very few moving parts, storage heaters need very little maintenance and don’t need to be serviced annually.


  • It is one of the most expensive heating options in UK and emits more CO₂ than most other systems.
  • If you work full time and do not require heating during the day, storage heaters may not be the best option as heat will be emitted even when you are not there, resulting in unnecessary energy wastage.
  • As storage heaters age, their internal insulation can break down; resulting in heat being expended too fast and so supplementary heating may be required for later on in the day.
  • The daytime rate on Economy 7 or Economy 10 tariffs is higher than on standard single-rate electricity tariffs, so while you’ll receive a cheaper rate for your heating, by running extra appliances during the day will cost more – particularly if you have to top up your heating with a secondary electric heater.