My tankless hot water heater started leaking. It ended up cracking the drywall, dripping through the ceiling of my first floor ceiling. I immediately called a couple plumbing companies and Fagnelli Plumbing were the only company available to come out at short notice. They advised me of a $60 call out fee which I agreed to pay. The technician who arrived hadn't had any experience with tankless hot water heaters, but made a call to his manager. He ended up tightening the fittings and presented me with a ridiculous bill. In total he was at the house for an hour and charged us $420 including the call out fee, to tighten 10 connections. The owner eventually agreed to refund part of the invoice. Make sure to get a quote before any work is completed so you aren't surprised by the final invoice.