A neighbours underfloor bathroom heating mat stopped working a while back, she asked me to look at it today. Turns out when it was installed the joiner had accidentally burst the cable for it. It's a small thin blue cable that heats up that has two conductors & an earth. Someone has done a repair on it underneath floor which looks like they have used proper kit, crimps, heat shrink etc. I've just took a voltage reading at the programmer which is fine going in & out & Ive peeled off the heat shrink & took a reading between each of the conductors & earth & on one I'm getting 150v & the other I'm getting 90v. Any ideas? Mat just needing replaced I'm guessing.