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Product at a glance

This product is discontinued

Immersion heater control

Electronic 7 is the digital equivalent of the Economy 7 Quartz timer, and is designed for use with Economy 7 and other more recent cheap-rate tariff arrangements. When water is heated by off-peak electricity, it is important that the immersion heater controller offers ease of use, coupled with the most efficient performance. This is where the Electronic 7 Series 3 controller comes into its own. Electronic 7 is designed to control one or two 3kW immersion heaters, utilising off-peak electricity tariffs to provide a full tank of hot water each morning. Additional off-peak settings are available to take advantage of the latest off-peak tariff arrangements. A boost button is provided to top-up hot water if supplies run low, and an automatic boost setting to provide a preprogrammed daily boost is also available.


  • For use with cheap rate overnight tariffs such as Economy 7 or similar to provide a tankful of hot water each morning


  • Can be set to accommodate utility tariffs that offer cheaper electricity periods during the day time
  • No clock to reset at Summer and Winter time changes
  • ‘Boost’ button - ideal for one hour top up without changing the set programme
  • ‘Boost’ element (in the tank) can be programmed so that it will heat only a small part of your tank at a set time each day
  • No loss of settings during power outages


  • Compatible with most cheap rate or Off-peak tariff structures
  • Electronic 7 is fully interchangeable with all past and present Horstmann/Secure Economy 7 controllers
  • Built in clock – automatic Summer / Winter time change
  • ‘Boost’ button
  • Timed boost programme
  • Up to 3 Off-peak settings per 24-hours
  • Programmable and manual boost
  • Programme security feature
  • Long-life battery maintains the clock, display and switch time settings throughout the life of the control
  • Suitable for use with single, dual or twin element immersion heaters
  • 7 years no quibbles warranty


Contact rating 13 Amps 230V AC Suitable for immersion heaters up to 3kw
Contact type Micro-disconnection on control, disconnection to immersion heaters on double-pole rocker switch
Supply 230V 50Hz
Pollution degree Degree 2 normal situations
Moisture protection Ordinary
Enclosure protection IP30
Shock protection Class 1
Live parts Enclosed
Operating temperature range 0°c to 35°C
Battery reserve Approximately 2 years total power disconnection
Clock am/pm Indication Winter/Summer indication
Programme options Off-peak – up to 3 On/Off time periods; Boost – programmable automatic boost and 1-hour manual boost
Dimensions 170 x 115 x 60mm (excluding rocker switch)
BEAB approved Yes