I'm sure this is like asking if hens have teeth, but is there such a thing as a wet underfloor heating pipe detector? I need to create a hole at the side of a concrete slab that contains wet underfloor heating pipes and I'd like to be doubly certain that I am not going to damage any of the pipes while doing so.
Have you considered using an infrared camera? Turn on your heating and when the pipes heat up it will show the line of hot pipes. Never tried this myself, just a thought
Thanks for the replies and good ideas. After hours of searching through my photo archives (printed photos of 30 years ago) I eventually located the photos I took just before casting the slab, and I was able to see that the area I'm planning on core cutting for a big pipe is completely devoid of any pipes. Crisis over!