Thanks for all the boiler advice and engineer recommendations above and by PM.
I ended up calling round loads of engineers to find someone who was working today and finally got a localish guy called Habib. He managed to fix it in a few minutes because it turned out that I had accidentally closed the valve next to one of the filling loop valves and that was stopping the water flow.
Maybe mark the valve, (with nail varnish etc) to show where 'Open' is,
or,
cable tie a reminder to the valve with the note
' No hot water? Check this is open'.
Thanks for all the boiler advice and engineer recommendations above and by PM.
I ended up calling round loads of engineers to find someone who was working today and finally got a localish guy called Habib. He managed to fix it in a few minutes because it turned out that I had accidentally closed the valve next to one of the filling loop valves and that was stopping the water flow.