24 hour water Heater time switch for single/dual or twin immersion Heater applications programmable every 15 minutes Suitable for combination storage/convector heaters with a 15 to 120 minute adjustable boost Indicator lights display on, Peak and boost outputs Contact rating of 16A at 230V 50Hz and a running reserve of 72 hours Comes with manual on/off switch Note Ensure that the On/Off switch on the back of the unit is switched to “On” when the product is installed Ensure the on/off switch on the back of the product is set to the “ON” position before mounting. If using one immersion element add a link between the off-peak and boost terminals using a solid copper core that is rated to carry at least 13 Amps. Also, check that the immersion element you are trying to switch is functioning by checking its resistance using an ohm meter. If unsure how to do this, employ the services of an electrician., Manufacturer: Tower Flue Components