pauliepie wrote:
Is it possible to have the heating circuit off a combi split into 2
zones, one for a ground floor the other for upstairs.
If so, what controls are required, etc,etc?

2 * 2-port valves etc, but you'll also need a bypass (e.g. pressure
relief bypass) so when the last valve turns off and tells the boiler to
stop theres somewhere for water to go while the boiler keeps the pump
running as it cools down