what normally happens when working with sparks that i get in to install ufh, they will test it ill prep floor they lay it ,i slc then they test again f every things ok ,ill lay floor,on this occasion client got his own sparky, told him to test before laying, which he did, where he fell off was cutting the end of the matt off and sticking the sensor back on, the client accepts its down to the spark, ive offered to remove tiles if he wishes,but he is going to live with no ufh,which defeats the object in my eyes,shamefull really