IS THE timeswitch AN HORSTMANN QUARTS. IF IT IS THE BOOST WILL WORK BUT THE OFF PEAK WILL NOT. IT IS A COMMON FAULT WITH THIS TIMESWITCH, TO CHECK your ELEMENT AND themostat.GET YOUR ELECTRICIAN TO OPEN THE timeswich AND SWOP connetion 5 WITH CONNECTION 4 AND swtch ON THE BOOST GIVE IT A HALF...