we've just written ours off (*) but we fitted this one :
http://www.rapidonline.com/Electroni...th-lead-122892
there's a longer cable version here :
http://uk.farnell.com/jsp/search/pro...003&sku=645424
and for pipes, we've used these :
http://www.rapidonline.com/Electroni...-sensors-76422
(*) it all tested OK before we started tiling but now, half-way through the tiling, the heating element is dead - no-one was careful enough (our place is still a building site), and we can't afford to lift the tiles & re-do ... so kit, sensor, controller, labour, all wasted ! We've tried using a stud-finder sensor to find the break, with the power on, but the tiles are too dense ...