John, New to BAC and my first post. Having had an internal coil split myself, if you are leaking hot water, my guess is you have an external leak which should be fairly easy to have fixed. If the leak is internal, you would have antifreeze pushing out through the overflow which on my hydro-hot came out around exhaust pipe. By external I mean that the leak my not be visible until the tin outer box and insulation are removed. Aqua-hot told me my unit, with an internal leak could not be repaired and had a replacement unit for about $8,500.00. I'm a farmer and have a fairly well equipped shop and some skills, and fixed the unit myself. I cut the back out of the internal box with a plasma torch made a new coil (about 30-40 feet) out of heavy copper tube, then welded the box back together. Any qualified welding shop could probably do the job. Hope this helps.
