After installation, your Dorma door closer will need to be adjusted to suit the weight of your door and the needs of the users. You can make your door close faster or slower to ensure it latches properly without slamming shut. There are two speed settings for the closing mechanism: one that regulates the speed from the open position and another that takes over to latch the door closed without slamming.
Things You'll Need
Hold the door open with a doorstop and have an assistant ensure the doorstop stays in position. Stand on a stepladder beneath the door closer and locate the pair of screws on the left end of the opener.
Turn the upper screw clockwise to decrease the amount of force applied by the closer when the door is released from an open position; turn it counterclockwise to increase the force. Repeat the process with the lower screw, which regulates the latching force.
Step down from the ladder, remove the doorstop and allow the door to swing closed. Notice how the door closer behaves differently with its new settings and make additional adjustments, if necessary, until it swings closed at a controlled speed and gently latches.