When I turn on my hot water tap it starts spurting out the tap rather than free flowing then after a minute or so it runs fine. It is affecting all my hot water taps. I live at the top of a tenement flat

What kind of a water heater furnishes hot water to the building? Gas or electric? Just one heater for the entire building or do you all have your own water heaters? Did this just start or has it been ongoing? Back to you, Tom