I've recently had underfloor heating fitted to my bathroom, but when it's switched on it trips the electricity in the house. I have had the wires tested that are under the tiles and it appears that the earth wires has crossed with the neutral wire. When I connect the heating using the live and neutral (no Earth wire connected) the system works fine and heats the tiles.
I want to know if this is safe to use like this. The tiles are sealed and grouted using a water repellent and the matt is laid into the sealant below the tiles.