I've set my Away to 10 degrees as well. Heating Off and Away have different use scenarios.
Heating Off is for summer when you just want to completely turn off the heating schedule but still allow hot water. Since it's summer there's no chance of the house getting extremely cold 5C is OK as an off setting.
Away mode is when you're away from the house, possibly for extended periods of time, and including winter.
The default for Away is actually 15C not 5C, as far as I can remember ?
I'm not guaranteeing that that's optimal for all installations - but on an installation where the system is having comms errors with the CS92A and other things have been checked it's certainly worth trying, even if it looks a little strange!
