http://www.esicontrols.co.uk/es1247b.html The ES1247B is a single channel electronic time switch and provides volt free output contacts making it an ideal solution for use with both line voltage and low voltage control circuits. The time switch can be configured for 7 day, 5/2 day or 24 hour operation for independent channels (all within the one unit). It is an ideal solution for combi-boilers, for systems having a common Heating and Hot Water zone, and for the control of additional heating zones. The wall plate used follows the industry standard pattern, as used by many of the other time control manufacturers. This allows for direct replacement often without the need for re-wiring. The new range of programmers hold a 3 year guarantee for consumer and installer peace of mind and are focused on value, quality and simplicity, offering an economical and durable solution for households.