Offpeak Storage

OffPeak heaters can be used as a background heating source or as a primary heater. OffPeak heaters store up heat when electricity is cheapest, and then release the heat at times when you most need it. It is one of the most economical heating methods.

A typical modern OffPeak heater takes around seven hours to fully charge. When internal bricks come into contact with the electric element, the heat transfers to the bricks. The heat is then distributed to the room by convection via natural or fan-assisted air currents. The release should be enough heat for 24 hours if the heater has been sized correctly for the room. Because OffPeak power is available for up to 11 hours a day, it means you should never run out of heat.

Modern OffPeak heaters look good and come fitted with charge controls, temperature sensors, safety cut-outs and improved insulation for maximum efficiency and safety. The main types of OffPeak heaters are:

Heat banks

These are used in living rooms – and an OffPeak heater of the right output will create a constant ambient temperature of around 16°C (background heat).

The fan is used to increase the temperature to a level that you require, typically around 21°C (main heat).

Midi banks

An OffPeak 'midi bank' (the generic name for a medium capacity storage heater) is designed to take the chill off the air for bedrooms and hallways. With no fans, the midi bank releases constant convection heat that will create an ambient temperature of around 16°C (background heat).


  • Runs on OffPeak power
  • Economical running and set-up costs
  • Generally considered a comfortable style of heat
  • Improved designs
  • Different types for different room applications


  • Slight fan noise on some heat bank models
  • Not an 'instant heat' system, overnight charge is required