As I understand it, the London Aire is supposed to have electronic controls for everything via a "System Control" app that is used with a "personal device, e.g. a smart phone. Are you trying to use the Silverleaf for that? Can you please explain a bit more about what you are doing and the nature of the problem? Are you saying the function to turn floor heat on/off or a/c on/off doesn't work, or that it doesn't even exist via the Silverleaf? And is this a Silverleaf problem or a Newmar problem? I don't see any Newmar claim that Silverleaf should be able to do this sort of thing.
Also, those are both thermostat controlled devices, so doesn't the thermostat setting include an Off position? Or is there no actual wall thermostat and electronic control is the only way to set it?
As you can see, I'm not familiar with the Newmar London Aire electronics, and I doubt if many others are either.