You are mot a plumber or heating engineer if you don't have one. My customers appreciate the worth of investment, they pay a £25 +vat charge and happy to do so. The machine is easy to use and fast, whilst freezing you can prepare your tools, whilst defrosting you can clear up, no mess, no drain off, no air locks, no inhibitor. You can allow a set managed amount of time, I really don't understand why engineers don't have one. I have bought mine 5years ago and never looked back. Finally quick, easy to use and takes the pressure out of plumbing and heating, thank you to freeze master