Also, make sure you have a repeater as close as possible to the King of Fans module. For re-pairing, having the hub really close might helpful, too, or at least I usually had better luck that way.
What really helped me here was replacing the antenna, and I'd highly recommend doing so if you're able to. It's really easy if you have access to the module--just a couple screws to open it up and a standard uFL (I think) connector for the antenna. The hard part for some people is that the fan is already mounted on an awkwardly high or angled ceiling. 
(Since doing this, I have had zero worries and was able to move the repeater I put as close as possible to somewhere I actually wanted it--and it paired through the mesh as soon as I reset it.)
