Apologies if its already been covered. I've been asked to quote on a heat only with a solar compatible unvented, the existing system is 10mm microbore gravity fed to rads. I'm confident of the conversion and have my gas safe and G3, I've also been been asked to provide an outlet for, and install ufh. My concern is that the Ufh will act as a bypass. What preventative would I need. Excuse the ignorance but I don't usually work on Underfloor. Thank you.