the display in bar for the cold water supply is showing that the boiler needs topping up, the white handle should be either on top or just above the red one but it's completely down...
You don't say what type of boiler you have, but a pressure guage on the front proberbly means that you have a combi.Somewhere on the system there will be a "filling loop" this is usually located directly below the boiler and is a braided hose with a lever valve on one end. Some manufacturers build the loop into the boiler if that is the case you will need to consult the user guide. in either case turning the lever valve until the guage reads 1 bar will cure the problem.Dont forget to make sure you shut off the valve when you have finished.
