Many homes rely on an electric immersion heater, whether as a primary source for their domestic hot water or as a “backup” facility to their main system (gas/oil boiler etc). Usually rated at 3 kw domestic immersion heaters can use significant amounts of energy and therefore proper control is essential particularly if it is to be used with an off peak/ time of use tariff.
Originally designed for use with Economy 7 off peak electricity tariffs, the Economy 7 Quartz is the standard by which all other immersion heating controls are judged and is the all time best seller in this arena. The Electronic 7 is an updated digital version with additional off peak settings. This makes it compatible not only with Economy 7 but also Economy 10 and most modern time of use/off peak domestic tariffs.
Economy 7 Quartz 1 hour 
Quartz controlled 24 hour timer with battery reserve and 60 minute boost timer. Single, off peak ON period. Suitable for use with 3kW single, dual or twin element immersion heaters in conjunction with Economy 7 tariffs or similar.
Economy 7 Quartz 2 hour 
Quartz controlled 24 hour timer with battery reserve
and 120 minute boost timer. Single, off peak ON period. Suitable for use with
3kW single, dual or twin element immersion heaters in conjunction with Economy
7 tariffs or similar.
Electronic
7 
Digital 24 hour timer with up to 3 OFF PEAK settings and manual and programmable boost. Automatic BST/GMT time change and back lit display. Suitable for use with 3kW single, dual or twin element immersion heaters.