How do I find the location of a leak in a hot water pipe which is under a tiled floor. That is without lifting all the tiles in a long hallway.

Chris Callery, January 2009

if you can access both ends of the pipe run
Drain pipe run
Plug one end
Jury rig a car tyre valve at the other end
Pressurise the line with compressed air/foot pump/whatever
Follow line of pipe along hallway with listening rod/tube
to your ear.
Very sensitive, works for me
Good luck!

Asanewt, January 2009