I have a mountain cabin where 2 water pipes, hot an cold, goes between the bathroom and kitchen. However, they tend to freeze in the winter. The obvious solution is to put a heating wire along the pipes, but access is cumbersome. So I have thought about following solution: I ensure electrical contact between the pipes at each end, and the pipes will now form a closed loop. In the bathroom, the pipes go parallell with 50mm distance over a length of 1m along the wall. For the rest of the distance, the pipes are closer. So I make a coil with many turns, square shaped, 50mmx1m, and put the coil over the parallel pipes. Plug the coil in the socket (220V 50Hz) Now the flux created by the coil hopefully induce a large current in the loop formed by the pipes, and whoops... the ice slowly melts away because of the resistive heating: Will this work? If so, how many turns do I need? I believe a total power of 200W would be sufficient, as the pipes are isolated and not much heat will escape to the surroundings. Would an iron core be of any help?