Dear all,
Many, many thanks i) to the person who had this problem before me, and ii) the public-spirited soul who posted the solution!
I am in northern France for a few days playing service barge / support vehicle in the California we bought new in August last year, but have since then hardly used, to my daughter in her part-camper-converted ex-British Gas Caddy whose transformation has been my full-time job since September (hence no real outings yet in our California!).
It’s still pretty cold here, so I managed to fire up the cabin heater (whose control interface I’m not very convinced by!) the night before last, which was nice. Last night I tried it again but it refused to get going, so I gave up, curious too that the overhead display seemed stuck in a waiting loop.
Surprise, surprise, this morning I couldn’t clear the screen to get to the main menu to drop the roof, so read the manual and set about dismantling the overhead facia to do a manual closure.
I wasn’t too happy with this route, given that I was sure some kind of an electrical reset would probably fix it, so I did a search and found this thread.
A quick extraction of first the 20A, and then the other under-passenger seat fuses, had the control screen back to normal and the roof dropped just as it should.
It dawned on me later that perhaps the cabin heater refused to function because my tank was down to about 40 miles range - I haven’t looked up a minimum tank level for the heater to be viable, but I’m sure someone’s going to tell me!
So, again, thanks folks for having put up such valuable tips - it really did save us a lot of aggravation this morning!
With best wishes; John.