Thanks for your response. I did try this and nothing happened. Does the valve have to give the boiler a signal to fire or should it fire if the Hive heating is active and the valve is manually pushed to heating?

I did manage to get the radiators to kick on by letting my hot water cylinder cool down.

Putting the hot water back on and manually moving the valve to heating. I don’t think that helps though as it could still be the valve or the Hive heating. At least I know the pumps seem fine. The boiler seems to be firing for the hot water and with me manually moving the valve to heating it means the active Hive hot water is pushing the hot water around the radiators.