My own boiler is on a RCBO so provided there is still power, even if all the other circuits trip, my boiler still works during a cold snap unless of course it itself breaks down or causes the RCBO to trip.

My alarm, smoke dets, CO dets and CCTV system is also on its own RCBO. And ditto all outside sockets and outside lights so the internal sockets and internal lights are not affected by outside events.