Things You'll Need
Allen wrench set
Many doors utilize a closer to ensure they shut slowly after opening. Over time, the valves that control the flow of air or fluid – depending on the type of closure – can lose their adjustment. When this happens, the door will close at a fast rate and slam shut. This is not only a nuisance, but it can also cause damage to the door components. Fixing the problem when noticed will eliminate door slamming and protect the door from severe damage.
Open the door.
Locate the valve adjustment screw located either on the front of the closure piston for storm and screen doors, or on the rear section of the closure body for heavier doors.
Use a Phillips screwdriver to turn the adjustment screw one-quarter turn clockwise to increase the piston pressure on screen and storm doors, or use an Allen wrench to turn the adjustment screw labeled "latch" on heavy door closures.
Close the door.
Continue turning the adjustment in quarter turn increments until the door closes at a normal pace and slowly latches without slamming into the catch mounted to the door frame.
Heavy door closures may also contain a second adjustment screw labeled “swing” or “S” that adjusts the speed at which a door closes until the “latch” adjustment kicks in. Adjust the secondary screw using the same tools and in the same quarter-turn increments as the “latch” screw.